laying a wash
A wash is a large area in a watercolor painting where the paint flow and diffusion have been manipulated to efface individual brushstrokes. Within wash areas, color transitions are usually gradual and span analogous hues.
Laying a wash a flawless portrait background or a landscape sky that shades from bright to mist is one of the most satisfying tasks in watercolor painting. It's a skill that takes practice to master, although the essentials are not difficult to learn.
As a novice painter, I discovered that the instructions provided in watercolor handbooks are often inadequate. You're sometimes told to use incorrect techniques, or to use a single approach in all situations. An example:
Set your board or block on a slant, raising the top edge about 1-1/2" to 2" off the top of the table. Load your 1" flat brush with paint and make a pass horizontally across the top of the paper. The paint will move downward, with a bead forming at the bottom of the stroke. Load the brush again, and make the next pass a little down the page, in the opposite direction, slightly overlapping the first. It's important to pick up the bead on each pass. Don't waste time: a line can form. It's also important to reverse the direction of the stroke with each pass. This will prevent a buildup of darker pigment on one side of the page. Repeat the process until the paper is covered.
That's the total guidance. Even the wash instructions in David Dewey's watercolor book, though unusually accurate and complete, still leave many things unexplained ... what happens when I use different papers, different brushes, different brushstrokes, different types of paints, different angles of tilt? How can I vary washes to get expressive effects?
The difficulty in learning watercolor is that there is too much going on at once. I found the only way to unlock the problem was to break the technique down into its basic components brushes, papers, pigments types, paint behavior, tilting the wash, brushstroke techniques, prewetting, application strategies then examine each component carefully, see what happens when I change or vary it, and finally put everything back together in a spirit of exploration and improvisation. That's the outline of this page.
As with any skill, the key is practice and more practice. A good way to start is to try out the wash strategies described on this page. Buy six or eight medium sized (10"x14") watercolor blocks, five or six with rough (R) or cold pressed (CP or NOT) finishes and one or two with a hot pressed (HP) finish. Select different paper manufacturers so that you get different qualities of paper and variations in finish. Use these up (paint on both sides) as you explore the different wash techniques described here. I guarantee you will feel it is time (and paper) well spent.
the setup, brushes & papers
For starters, a few aspects of wash technique are part of your general painting methods and only require brief comment. These include the setup, brushes and papers.
The Setup. Every painter develops a personal, habitual setup for painting. This work space depends on the space available, the painter's physical comfort and stamina, the typical size of work, and the artist's preferred painting technique. But a few specific requirements are necessary for proficient wash application.
The essential thing is a clean and uncluttered working area. Everything extraneous to the wash task pencils, brush holders, coffee mugs, tubes of paint must be stowed or cleared to one side. All surfaces must be clean of dirt, hair, pencil shavings, eraser rubbings, drips of paint and anything else that might stray onto the paper.
You also need a a tiltable work surface the paper should lie on or be affixed to a hard, flat surface that can be tilted quickly to any desired angle. Some painters use a tiltable drafting table, which gives maximum control and comfort. Some work on the floor and tilt the surface by lifting a corner or edge of the sheet this gives good control, but crouching to paint is physically tiring.
My work surface is a compromise: the largest dining table I could find retail (about 4 by 9 feet, from Crate & Barrel), set away from the walls so it can be addressed from either side. This is my "floor". Paper rests on two or three sheets of Daniel Smith's watercolor board, 23" x 31", propped on a long strip of 2x2 or 4x4 lumber. This is my tilt, which I manipulate by turning, lifting or bending the sheet from the edges, or with a system of lumber and weights.
a generic wash setup
You'll also want flat, reachable work space to hold all your incidental tools within easy reach. In my setup, this is the table on either side. Painters who use a tiltable drafting table set their tools on a taboret or nearby bookshelf.
The wash mixture, or paints used to build the wash, should be in a separate container located close to the painting. Some painters mix their wash solutions in the mixing area of a flat palette, eldajon palette or butcher tray, which lets them swirl in a bit of fresh paint to adjust the mixture on the fly. I use a system of separate mixing dishes and premix all paints before starting work.
Whatever your system, if the paints are not set close to the work, you'll find yourself making a rapid swing from paint to paper that can cause a hasty splatter. The container should be heavy and squat enough that it does not tip over if accidentally struck with the hand.
Always mix up a generous quantity of wash mixture, more than enough to cover the entire area you want to paint, with slop off the sides. Running out of wash mixture before you are done is always fatal to the wash. But mix up a punch bowl, either. I find one tablespoon is just enough to cover a moderately sized full sheet.
Finally, a water supply primarily for prewetting the sheet and gradating the wash density. (This should not be the brush rinse water.) I use both a bowl and a spray bottle.
Other tools are useful. It is prudent to have paper towels at the ready, and a roll of towels within reach, to absorb excess runoff, blot or shape the wash edges, and catch drips before they sink into the paper. Many artists use hold fasts bulldog clips, binder clips, carpenter's spring clamps (right), tacks, tape or weights to hold the paper in place when it is tilted or to control cockling or warping. (Chinese painters use narrow lead weights to hold down their rice papers, but these may be insufficient for heavier cellulose papers and can slide if the support is tilted.) Many painters use tape, masks or resists to reserve areas that the wash should not cover, or sheets of paper anchored with drafting tape to protect unpainted areas of the paper from drips or splatters.
Should you stand or sit? Half sheet or smaller works are easy to bring off while sitting, though larger works are awkward to do. For small paintings, I prefer to sit on a small stool that raises me above the work but that I can kick aside to stand if necessary.
If you find yourself rearranging tools and materials as you work, or putting tools down in a place different from where you picked them up, then reconsider your setup. You want to avoid any interruptions created when you have to stop and look for something, and especially the interruption created when you knock something over. Don't fight it: start by putting things where you conveniently or normally reach for them, and clear away everything else.
A fresh, flawless wash usually requires a rhythmic and uninterrupted performance. You can't stop in the middle to answer the phone, let out the cat, or look for a different brush. It's tricky to go back and do a small section over. Once you start, you're committed to finish. That's part of the challenge and the fun. Take the phone off the hook, let out the cat, and you're ready to start.
Brushes. The common advice is that you should use the largest brush practical for a wash. In fact, you can lay down a wash with almost any brush, but some brushes make the task easier than others.
Most painters go to a 1" or less flat brush (bright or one stroke) or a #16 to #12 round brush; the flats are especially useful for carving precise edges or wedge shaped cutouts, or for "scrubbing in" pigment or paint over an area of especially rough paper texture, a folded deckle, or a blotch of water repelling tub sizing.
However, in many situations a smaller brush a 1/2" flat or a #8 round may be the best tool for the job. A smaller brush is desirable when the wash area is not too large, the wash contours are too complex to render with a large brush, or the wash contains cut out areas (such as white clouds in a blue sky) that create spaces too small for a large brush to maneuver. A smaller brush can also create subtle texturing variations, that may be desirable in areas that represent the surface of water, grassy fields, and so on. Make your brush choice alertly: don't get locked into a single approach.
Of course, there are specialty wash brushes designed specifically for the job. These have a very fat tuft (usually 1/4" or more thick, and more than 1" wide), soft, long bristles, and a large carrying capacity. They will take up a lot of paint and release it in an even flow, but they are too bulky to define precise contours at the wash edges. Traditionally they are used with resists or masking to define the wash edges, or are used to lay down a sheet wide wash area that is painted over with the edge defining shapes.
A few artists use Japanese hake brushes for large wash areas. I find these brushes are good for smoothing out a wash that I have already laid with another brush, or an area charged with additional paint. These brushes do not have enough carrying capacity or edge control to be useful as the primary application tool. The "old school" brushes, with the tufts set in a row of bamboo shafts, also shed hairs like a scurvy dog, no matter how many times they've been used before.
On that point: don't try to brush hairs or debris out of a wash while it is still wet. Usually a dilute or granulating wash will dry under the object without a trace. If the paint is more concentrated, or the object is large enough to pull paint underneath itself, I keep a pair of fine tweezers handy to pluck out debris if necessary, but this must be done before the wash has begun to dry.
Whatever brushes you use, I find it is helpful to have a second editing brush at the ready, premoistened with the wash solution and shaken out. (Don't moisten with pure water, unless you intend to dilute the wash color.) A filbert brush or smaller sized round brush is most useful to refine the wash edge around areas of more detail, smooth out a blotch of coarse pigment, or soak up small quantities of excess wash.
I suggest you purchase and use the large wash brushes only after you have practiced your wash technique with a #12 or #14 round and a 1" flat. The larger wash brushes can conceal a lot of faults in your technique and give you excellent results in big areas, but someday you will need to paint a wash that requires detailed edges or complex patterns where the standard wash brush is too big or clumsy to maneuver. If the big wash brush is the only brush you know how to use, you're stuck. If you can lay a good wash with the standard brushes, then using the specialized wash brushes will be a pleasure.
Papers. You can lay a wash on almost any kind of paper, but some papers make it easier than others.
The best paper for good wash results is moderately sized with a moderate surface finish or tooth (cold pressed or a gentle rough pressed). If the surface texture is too heavy, you will have difficulty laying down the wash mixture without pinholes popping open over the paper indentations, especially for active pigments. It's possible to lay a flat or evenly graded wash on hot pressed (HP) paper, but the paper will ruthlessly show any irregularities in your wash mixture, brushstrokes, or brush wetness. However, if you want a wash to show painterly, expressive variations, then hot pressed may be ideal.
a variety of clips, clamps
Most painters prefer the paper stretched, or of a sufficiently heavy basis weight (400 GSM or higher) that it will not cockle or warp when wet. Note that a heavier basis paper generally has a slightly rougher surface texture.
All painters discover, once they have matured their technique, that it is straightforward to complete a single wash application before the paper absorbs enough moisture to cockle (especially if the paper is tilted to drain the excess paint downward), and it is relatively easy to lay a second wash over moderately cockled paper, provided that the brush pressure is kept constant across the paper surface and the paper is tilted enough to prevent puddling.
The surface of the paper must be absolutely clean, free of any oil or dirt from your fingers or the painting surface. Nothing is more disheartening when you are most of the way through a perfect wash than to hit a skid of invisible grease or heavy surface sizing that repels the paint to make an ugly white blotch. If this happens, stop and give the area a quick, vigorous, all over scrubbing with the brush tuft, then retrace from the wash stroke above and continue downward.
pigment & paint behavior
Most wash tutorials give the impression that paints don't matter in your wash technique: all wash mixtures can be applied in the same way. This assumption is a legacy of "color theorists", who teach that paints are just "colors", so one "brown" or "blue" wash mixture is just the same as any other.
In fact, painters make paintings with paints, not with "colors", so the types of paints in a wash mixture have a major effect on the quality of the wash and how the wash should be applied. In addition, the pigment behavior depends on how much the paint is diluted with water. So painters need to consider both factors before they apply the paint to paper.
The behavior of pigment particles depends primarily on three things: (1) the weight of the pigment in water, or its specific gravity; (2) the average pigment particle size; and (3) the color difference between small and large pigment particles. These differences in pigment behavior are enhanced by diluting the paint with water, which thins out the vehicle ingredients.
Basics of Pigment Behavior. Let's consider first how pigments behave when suspended in water.
All paints contain millions of microscopic pigment particles. These particles are not all the same size, but form a particle size distribution, as shown in the figure. It's the same with sand at the beach, gravel in the road or stones in the river bed: there is a size variation around the average. These variations are always present, and the distribution of sizes has a similar shape, regardless of the average size of the particles.
pigment particle size distribution
In pigments that are relatively light in water and have a very small average particle size, even the largest pigment particles are kept in suspension indefinitely by continuous jostling of water molecules. Like an infusion of tea, the solution remains the same even if left undisturbed for several days.
The contrasting behavior of heavy pigments is probably familiar to you. If you mix up a quantity of water and a grainy mineral pigment, such as viridian, cobalt blue or manganese violet, then let the mixture sit undisturbed in a clear glass container, the paint visibly begins to separate after a few minutes.
settling of pigment particles in a wash solution
The heavier particles sink to the bottom, while the lighter particles remain suspended. How much of the pigment settles out depends on the weight and size of the largest particles, but the separation always becomes more pronounced if you let the solution sit overnight: the concentration of paint changes from nearly transparent at the top of the solution to nearly opaque at the bottom.
This variation in particle size might be trivial, except that in pigments with medium to large particle sizes, pigment color can change with particle size: smaller particles are typically a different hue, and typically are lighter in value. In fact, by manufacturing pigments to different average particle sizes, pigment manufacturers can adjust a pigment's color, hiding power, lightfastness and other attributes. So many heavy pigments are really mixtures of two different paints one made of coarse, saturated particles, and the other made of whitish, light particles.
You can observe this by mixing up a moderately diluted solution of cobalt teal blue (PG50) in a flat bottomed highball or drinking glass, then letting it sit undisturbed for two days. Examined from above, the paint will seem to have changed color to a dull bluish gray, but this is because the smallest cobalt particles, which are whiter and bluer, have settled as an opaque layer on the top. Scrape this layer aside with a brush, or look at the container from underneath, and the larger, bright turquoise particles become visible.
Basics of Paint Behavior. Two additional factors depend on the paint formulation and how much the paint is diluted with water.
Paints contain many other paint ingredients besides pigment, including binder, plasticizer, humectant, filler and dispersant. These invisible ingredients are also dissolved or suspended in the paint solution, and they often affect how the visible pigment disperses, flows, settles and backruns when diluted with water and applied to paper.
The proportion of pigment in a paint varies across paint brands and types of pigment or paint. In general the proportion of pigment is smaller in low quality or inexpensive ("student") paints, and in high quality paints that are made with strongly tinting pigments (such as the phthalocyanines or dioxazine) where a little pigment goes a very long way. The proportion of pigment is also smaller in pigments with very small particle sizes, because the total surface area of pigment particles increases as the individual particles get smaller, and this larger total surface area requires proportionally more vehicle to cover or "wet" completely. Finely divided pigments are also more likely to be formulated with a dispersant to aid in milling (mixing pigment and vehicle) when the paint is made, or with fillers to moderate an excessively high tinting strength.
Both aspects of paint formulation mean that the pigment behavior or "pigment personality" depends both on the type of pigment in the paint and the manufacturer (brand) that made the paints. The primary way the painter controls the effect of vehicle ingredients on pigment behavior is through the brand of paint you choose. Most modern watercolors, such as DaVinci, are formulated so that all "colors" behave the same, regardless of the pigments in the paints. M.Graham tube paints, and especially the Kremer pan paints, which contain pigment, gum, glycerin, sugar and little else, show a wider range of pigment behavior. Student paints often rely more heavily on dispersants to reduce the time required to mill (thoroughly mix) the paint, but the dispersant causes these paints to diffuse rapidly when applied wet in wet.
However, you usually must add water to the paint to get a suspenison of pigment at the right concentration, and the more water added to the paint, the less effect vehicle ingredients have on pigment behavior. So paint brands tend to behave more alike, and pigments tend to behave more differently, as they are more diluted. This is the second way that the painter can control the effect of vehicle ingredients on pigment behavior.
Wash Mixture Guidelines. To sum up: the pigment behavior in a wash is determined by three pigment attributes weight in water, average particle size and hue variation across particle sizes. The quantity of dispersant in the paint, the proportion of vehicle (binder, humectant and plasticizer) to pigment, and the proportion of paint to water (dilution) also change the paint behavior; but these effects are weaker in heavily diluted paints.
These basics of pigment and paint behavior suggest these important wash principles:
concentrated paints impede diffusion and flow, and magnify differences in the rate of evaporation between paint areas of different wetness, producing irregularities in the wash
diluted paint mixtures more easily produce a flawless paint application with no visible brushstrokes, but enhance pigment effects related to weight, size and color variation
heavier particles sink faster than lighter particles to the bottom of a diluted wash solution
larger particles sink faster than smaller particles the smaller particles are kept suspended by the jostling of water molecules around them
larger vs. smaller particles separate in a wash: and if there is a noticeable color difference between large and small particles, then their separation creates a visible color separation as well.
Active pigments. These pigments are very light (specific gravity under 2.0), have a very small average particle size (less than 0.5 micron), and little color variation across particle sizes. They include iron blue, carbon black (specific gravity 1.8), phthalo blue, dioxazine violet (1.6), indanthrone blue (1.5), and most of the quinacridones. Excepting the iron oxides, active pigments have high tinting strength and therefore comprise less than 20% of the total paint volume (a vehicle to pigment ratio of at least 4 to 1) most of what you apply to the paper is binder, plasticizer, humectant and filler. These vehicle ingredients increase the osmotic difference between paint and pure water, causing the pigments to diffuse more aggressively wet in wet, and to dry more slowly. The light, small pigment particles are also more easily moved along by capillary flows that occur in the last stages of drying, which creates backruns and other visible imperfections in the wash texture. They often diffuse or shoot wildly across wet paper, because a dispersant has been added to the vehicle to help it completely wet the extremely small pigment particles, which tend to clump or cake during milling. (Ultramarine blue and ultramarine violet, though they have much larger particle sizes, can behave like active pigments when dispersants are used to wet the pigment particles during milling.) In general, active pigments apply smoothly, but are susceptible to diffusion and backruns.
Heavy Pigments. These have a specific gravity of 3.5 or more, a medium to large average particle size (on the order of 5 microns or more), and significant color variation across particle sizes. Pigments of this type are mostly metallic crystalline pigments such as viridian (specific gravity 3.5), cobalt violet (3.8), manganese violet (3.9), cobalt turquoise (3.9), cobalt blue (4.0) and cobalt green (4.1), and some red iron oxides labeled "transparent" that in fact have a granulating texture. Because larger pigment particles require less vehicle to be thoroughly wetted, the pigment usually comprises more than 40% of the paint by volume (a vehicle to pigment ratio of about 1 to 1). The thicker vehicle makes these paints more likely to streak or show brushstrokes if applied at high concentrations, and are especially difficult to apply evenly to dry paper. The vehicle usually contains proportionately more gum arabic and glycerin to prevent the large, hard, heavy particles from separating out in the tube, and contain the least dispersant. The large, heavy particles rapidly sink out of a wash solution, which must be stirred each time the brush is charged, or they will produce a dark blotch where the brush first touches the paper. But they do not diffuse wet in wet and are resistant to backruns even when rewetted with paint or water, and blotches or irregularities usually can be smoothed out with a brush while the paint is still wet.
Muddy Pigments. Finally, there are some exceptional pigments that are both very heavy (specific gravity above 4.0) yet have average to small particle sizes (0.5 micron or less) and little color variation across particle sizes. In most brands of watercolors, these include the red, orange and yellow cadmiums (specific gravity 4.4 to 4.5), chromium oxide green (5.1), red iron oxides (venetian red or indian red, specific gravity 5.2), any opaque but nongranulating umber, sienna or ochre, and chinese white (5.6). These paints have a dense, opaque texture caused by the heavy pigment specific gravity, the small particle size, and the relatively limited variation in the size of particles (or particle aggregates) produced by the methods of chemical synthesis and finishing. They usually have a high refractive index, low tinting strength and in many cases a relatively dull color, so more pigment must be used in a wash to obtain the same color density as other paints. The proportion of gum arabic or glycerin in the vehicle is higher than in average pigments but not as high as in other heavy pigments (cobalts). In dilute solutions they are as likely to backrun as the active pigments, are resistant to backruns when moderately or heavily diluted, but are likely to cake, streak or bronze when applied near full strength.
Average Pigments. What remains are the pigments that do not fit into any of the previous categories. These usually have a specific gravity between 2.0 and 3.5, an average particle size between 0.5 and 1 micron, and consistent color across all particle sizes. Nearly all of these average pigments are synthetic organics (most of them laked dyes), yellow iron oxides, and a few synthetic inorganic pigments such as nickel titanate yellow and the metal azomethines. In these paints the pigment usually comprises around 30% to 40% of the total paint volume (a vehicle to pigment ratio of about 2 to 1). Most watercolors are manufactured so that these "average" pigments behave the same way: relatively inactive wet in wet, consistent across different concentrations of paint and water, and producing a flat, textureless color no matter how they are applied.
Pigment Mixtures. Very often the paints mixed in a wash solution contain two or more pigment types. The painter can manipulate the wash behavior by the choice of these pigment combinations.
Heavy + Muddy. The mixture of two granulating or powdery mineral pigments (synthetic inorganic compounds of cobalt, cadmium, manganese, chromium or iron) of very different particle sizes is the most difficult of all wash mixtures to control. The crystalline components settle out of solution quickly, but at different rates, and usually one pigment is more concentrated in the first touch of the brush. Painted with juicy, randomly varied brushstrokes on flat paper, these mixtures dry with a mottled, mineral appearance, but it is very difficult to get an even, flat color.
Active + Heavy. An especially versatile mixture consists of a granulating or powdery mineral pigment (a heavy pigment, such as viridian or a compound of cadmium, cobalt, manganese or magnesium) with a synthetic organic or "staining" pigment (such as iron blue or any quinacridone, phthalocyanine, perylene, dioxazine or benzimidazolone). The synthetic organic pigments produce a bright, consistent and strongly tinting basic color, and create subtle color variations in concentrated applications due to small backruns; the heavier mineral pigments mute backruns and induce pigment texture in diluted, juicy applications, and importantly reduce the staining behavior of a concentrated mixture, making the paint easier to lift or edit.
Wash mixtures normally should be stirred each time the brush is charged, otherwise the heavier pigments (cobalt teal blue in solution with a phthalocyanine) or heavier pigment particles (in grainy pigments such as cerulean blue or cobalt violet) separate in solution. However an unstirred wash mixture provides the painter with a simple method to modify the paint color on the fly, by the way the brush is charged with new paint. If the brush is dipped into the surface of the wash mixture, it only picks up the smaller, lighter pigment particles, which usually provide a more fluid color. If the brush is swept along the bottom of the container, it picks up the heavier, coarser pigment particles and usually leaves a heavy paint concentration or grainy blotch where the brush first touches the paper.
Active + Muddy. These mixtures produce similar paint behavior as the active+heavy mixtures, with two exceptions: the smaller particle size of the muddy paints makes the mixture more susceptible to backruns at all concentrations, and typically makes the mixtures more staining.
Active + Active. These mixtures, for example a phthalocyanine with a quinacridone, are very stable in solution. On paper, slight backruns may cause the two pigments to separate, producing very subtle, feathery contours of color within the wash area. These can be produced by brushing upwards into the previous was stroke after each new stroke is applied, or by lightly stroking satin wet wash areas with a thirsty or wicked brush. The amount of color variation depends on the specific pigments and brands of paint in the mixture and the absorptance of the paper, and must be discovered by trial and error.
Average + Heavy/Muddy/Active. The "average" pigments generally mute or buffer the attributes of any of the other pigments, but the amount of change depends on the specific paints used and their concentration in water.
Decanting Pigments. If you require a granulating (usually blue or violet) pigment for one reason or another (hue, mixing behavior, lack of alternative paints), but want to minimize the paint texture or pigment separation, or pigment banding during the wash application, a traditional remedy is to decant the paint solution.
In the 19th century, the procedure was to pour the wash or paint solution into a paper cone (like the paper cups used for "snow cones" today). The largest, heaviest particles sank into the point of the cone, out of reach of the tip of the brush. The paint mixture could then be drawn directly from the cone (though the solution had to be regularly stirred to keep the smaller particles in suspension, while the heavier particles would quickly sink back out of reach), or the bottom of the cone could be pinched with thumb and finger (to trap the heavy particles in place) and the rest of the paint solution poured off into a mixing cup.
The same trick works well today, and if you can't buy the snow cone cups at a party supply or culinary supply store, use a sharply tapering cocktail glass (some martini glasses work fine), or a funnel rolled from heavy waxed paper with the tip folded upwards to seal the bottom.
I prefer something simpler: I mix up the paint in a mixing cup, let the paint settle for an hour or so, then decant the paint by pouring it off into a second mixing cup. A sludge of the largest pigment particles remains behind. (Keep in mind that decanting off these largest pigments will usually alter the paint color.)
tilting the wash
A traditional component of wash technique is the tilt of the painting surface. The tilt creates a fall line or directed gravitational flow across the paper. This pulls the wash solution from high to low and collects the excess liquid in a reservoir, called the wash bead, along the bottom edge of the last brushstroke.
the downward flow of the wash bead
Each brushstroke cuts into the existing wash bead and creates a wetted area underneath it, allowing it to flow down the stroke to the new edge. This downward flow has three functions:
It erases brushstroke edges, by flowing perpendicularly (across) the horizontal direction of the brush.
It equalizes variations in the quantity of paint applied in successive brushstrokes, producing an even concentration of pigment down the paper.
It prevents upward backruns as paint is applied, and makes it easy to wick up excess paint with a thirsty brush.
The question is, how much of a tilt should you use, and why? Watercolor tutorials differ as to the optimal tilt to use. The advice quoted above suggests 2 inches which can be almost any tilt, depending on the size of the painting support. Rex Brandt suggests you tilt the surface to 15°; David Dewey suggests 40°.
First, let's make the inquiry: what are the actual limits on the tilt you can use in painting?
If you lay horizontal brushstrokes of clear water on watercolor paper, one below the next, tilting the surface upwards at a greater angle as you go, eventually the wash bead will break and run down the paper. This usually happens when the tilt is around 40°. So 40° is the upper limit on a tilt that still lets you confidently control a wash.
If you pour a teaspoon of pure water on a flat watercolor paper, then slowly tilt the surface upward, the puddle of water starts to run downwards at a tilt of about 6°. Because gravity does dislodge this large puddle of water if the tilt is below 6°, there is little or no tilt effect below 6°.
A little trigonometry shows that you get a tilt of 40° by raising the back edge of the painting support by about 2/3d's (64%) of the support height. That is, if your drawing surface is four feet from top edge to bottom edge, you must raise the top edge so that it about 2-1/2 feet higher than the bottom edge to get a 40° tilt. A 6° tilt requires you to raise the top edge by about 10% (or 5 inches/4 feet).
the painting surface at a 15° and 30° tilt
Within this range, there are two convenient benchmarks. A 15° angle is obtained by raising the top edge of the drawing surface to a height equal to 1/4 of its top to bottom dimension. A 30° angle requires a tilt of exactly 2/4 (or 1/2). These proportions are easy to judge by eye.
How does the tilt affect the paint behavior? As you increase the tilt of the watercolor surface, several things happen:
1. Greater tilt causes more water to flow from the top edge to the bottom edge of a new wash stroke in the time between strokes; this water collects into a tighter, larger bead at the bottom edge of the wash, which is more likely to break and run down the paper. So the tilted wash forms a larger wash bead that is more likely to drip and therefore must be watched and manipulated with more care.
a tilted wash forms a larger wash bead
brushstroke viewed from the side
2. Because a greater tilt causes the wash solution to flow more quickly off the surface of the paper, the tilted wash dries more quickly from top to bottom than a wash painted on flat paper. This leaves less opportunity to brush out small imperfections and less leeway to vary the tempo of your brushstrokes.
a tilted wash dries more quickly
3. As the tilt increases, more pigment is swept into the wash bead by the faster water currents and force of gravity, leaving less pigment on the paper above; as a result the tilted wash leaves a lighter color than a wash painted on flat paper.
a tilted wash has a lighter color
4. There is increased gravitational resistance to the capillary pull upwards of water in the new wash stroke, caused by the evaporation of water from the previous wash strokes; this capillary pull can cause backruns. So a tilted wash is less likely to backrun as it dries, because excess water is drained away. (Backruns can still form from a wash bead that is not wicked up from the bottom edge of the wash.)
5. The optimal wash brushstroke is achieved with the brush handle held nearly vertical to the ground and perpendicular to the paper surface. This is also puts the least strain on the wrist. The tilted wash brushstroke impairs brush action by forcing the brush toward a horizontal angle to the ground (if it is held perpendicular to the paper) or forcing an oblique angle of contact with the paper (if it is turned vertical to the ground); the increased angle also forces the wrist into an uncomfortable extension.
a tilted wash can impair brush action
6. More of the large pigment particles are swept into the wash bead by the faster water currents, rather than coming to rest on the paper where they are applied; but these large particles settle quickly on the paper underneath the wash bead before the next brushstroke can be applied. The tilted wash brushstroke shows heavy pigment banding, while a flat stroke has none.
larger pigment particles form bands in a tilted wash
brushstroke viewed from the side
7. The increased water flow and paint movement downward effaces any unevenness in the density of pigment applied by the brush or marks left by separate brushstrokes; so a tilted wash creates more even color, especially on a dry painting surface and for average or active pigments.
Some watercolor books explain that, in a tilted wash, the wash bead presses with a greater volume of water against the lower edge of the stroke, and this inhibits evaporation or capillary action along the "dry" edge of the wash area that can form a hard edge of paint by drying. But you have to be pretty stingy with paint application in order for this to happen.
If a hard edge does begin to form, it can usually be scrubbed out with the brush as the next brushstroke is applied. In addition, the appearance of dried edges can be better controlled by prewetting the wash area.
The ease of applying a wash when the surface is relatively flat the paint can be applied more quickly and with less worry about managing the wash bead, especially around "cut out" forms actually compensates for the supposed advantage of a tilted painting surface. Overall, tilting the painting surface is not the most effective way to control whether edges form in your wash area.
This means there are really only two unique benefits to tilting the paper (#4, fewer backruns and #7, more even color), and several potential drawbacks (primarily #5, impaired brush action and #6, pigment banding; but often also #1, larger wash bead, #2, too rapid drying and #3, lighter color). Tilting therefore seems overall like mixed bag. All things being equal, we should tilt the paper no more than necessary just enough to get the beneficial effects, but not enough to amplify the drawbacks.
If we view the wash benefits in terms of the four types of pigment, then three basic approaches emerge:
For active pigments and concentrated muddy pigments, the pigments are usually homogenous enough to minimize brushmarks and banding. The benefits #4 and #7 are most important, and too rapid drying (#2) is a significant hazard because it can induce backruns from the wash bead. So the principal goal is to tilt the wash far enough to prevent backruns, provided this does not aggressively drain the color or cause the wash to dry too quickly. This can usually be accomplished by using a tilt of 15° or more.
For average pigments and diluted muddy pigments, the benefits #4 and #7 are relatively less important the capillary forces that can cause backruns are not as strong, and these paints usually apply very smoothly at moderate dilution. But their lower tinting strength makes drawback #3 more significant. So the tilt should be just enough to smooth out the wash (keep the wash bead moving down the page to efface brush strokes), while minimizing the drawbacks caused by the increased downward flow. This can usually be accomplished by using a tilt between 6° to 15°.
For heavy pigments, the wash bands formed by the largest particles form more quickly the more the painting surface is tilted, and for most heavy pigment paints (the cobalt paints, especially) backruns almost never occur unless they are mixed with a different type of pigment. For these wash situations the best approach is often to use a minimal tilt or to paint the wash on flat paper and then immediately but very slowly tilt the paper to drain off the excess liquid (as described below). This can usually be accomplished by using a tilt of 6° or less.
Once the wash application has been finished, the tilt may be sharply increased up to 90° if desired to drain the paint more forcibly and produce a greater blending or smoothing effect on paint irregularities or color transitions.
These tilt recommendations apply to a diluted wash mixture as it is brushed on. Thicker paint mixtures must be applied at a more extreme tilt, sometimes 60° or more, to compensate the increased viscosity of the paint mixture with an increased gravitational pull. Thicker wash mixtures may show no water movement at tilts of 15° or less, color gradients or imperfections are blended less forcibly by extreme tilting, and backruns caused by too rapid drying (#2) are more of a hazard. If a high color density is required in the wash, a smoother wash texture can always be obtained from two or three diluted applications, rather than one thick application.
The tilt no more than necessary rules depends on the dilution of the wash mixture and the type of paint, paper, paper surface and brush you are using, as well as the wash appearance you want to achieve. You learn to navigate the nuances through experience. But the rule is a useful starting point and can guide your judgment as you look for the right solution.
Now we turn attention to the brushstroke, which is the primary way that the wash bead, pigment banding, backruns and other paint behavior is controlled in a wash.
All watercolor handbooks recommend applying the wash with quick, even, horizontal brushstrokes. Yet the brushstroke is an aspect of technique that you can (and should) adjust to suit the pigment and the kind of wash texture you want to achieve.
Holding the Brush. To find the best way to grip the handle of your brush, consider the different ways you will need to adjust the angle of the brush to the paper.
right and wrong start to a wash brushstroke
When you start the new stroke, always brush upwards into the wash bead from the dry paper underneath. Do not dip the brush into the bead or into the lower edge. This will break the liquid's surface tension, but provides nothing below the water to stop its downward flow.
If you are using a round, gently pull the brush upwards into the bead. If you are using a flat wash brush, touch the lower corner of the tuft at an angle to the paper, then press the brush to lay it flat against the paper, touching the wash bead with the upper corner. These movements set the brush tuft as a cup or wall under the bead before you break its surface tension, so any drip of water is caught before it gains momentum.
To make a smooth wash, hold the brush handle as near to perpendicular to the paper as you can without limiting your arm movement or cramping your wrist. A vertical brush increases the liquid flow from the tuft and also strikes the tips of the hairs against the paper: this helps to fill in pinholes on the paper.
If you want to show more of the paper texture (or the texture of the brush bristles), then hold the brush with the handle nearly parallel to the paper surface. This reduces the rate of liquid flow from the brush, and hits the paper with the sides of the hairs instead of the tips: both contribute to make a scratchy, irregular wash application that highlights the texture of the paper.
Third, unless you are scrubbing the paper to disperse heavy pigment deposits, dissolve surface impurities, or cover up the texture or pinholes in a rough paper, lightly touch the brush to the paper with just enough pressure to maintain contact. This draws the pigment evenly from the brush (rather than extruding it with pressure), and spreads the pigment evenly across the stroke. Heavy pressure forces the paint away from the center of the stroke and toward the edges; a light touch also keeps the bristles from pressing heavy pigments deep into the paper texture.
Finally, many washes must be applied around the edges of objects that are perceived to stand in front of the wash area, and these "cutout" edges must be painted cleanly and accurately. These edges usually require flexible wrist movements, which are more difficult if the wrist is held at an awkward angle.
Try different ways of gripping the brush until you find one that gives you the most flexibility to perform these four essential brush movements upward movement at the start of the wash stroke, perpendicular angle to the paper, gentle pressure across the stroke, and flexible wrist movements. You should be able to perform these across a wash stroke of any length with any type of brush you want to use.
Three Wash Brushstrokes. Now, what pattern of brushstrokes should you use? The diagram shows the three basic types of wash stroke patterns.
The straight brushstroke (left) is the commonly recommended approach. The strokes are made to overlap just enough to break the wash bead at the bottom of the previous stroke. The top edge of the brush passes through the bead in the stroke above, breaking the tension along the bottom edge and allowing the excess paint and water to flow across the width of the new brushstroke and form a new wash bead along its bottom edge.
You must alternate the direction of the brushstroke to keep the pigment coverage even: either by brushing in the opposite direction over the stroke you have just made, or by switching direction from one brushstroke to the next. If you always start at the left (or right) edge of the wash area, the bead is large on that side and small on the opposite side, where the brush has little liquid left. This can cause irregularities in the wash color, or backruns. A back and forth stroke also improves pigment mixing, as shown in the examples below.
pigment mixing in horizontal wash brushstrokes
left to right only (left) or alternating directions (right); tilted surface, first stroke is yellow, all other strokes are blue
At the start of each new straight stroke, most of the paint applied to the paper is actually drawn right out of the brush: the paint in the wash bead flows downward only toward the end of the stroke, when the brush runs out of liquid. If all the strokes are made in the same direction, the concentration of paint is not the same on the two sides of the paper.
The straight stroke is fine for average pigment washes: but with active or heavy pigments it causes three annoying problems. You are locked into a fairly mechanical rhythm, completing one horizontal stroke all the way across the page before starting the next, which limits your ability to handle complex edges or cutout shapes, such as clouds, in the middle of the wash. Second, you must work as quickly as you safely can, because the longer the time between strokes, the more visible imperfections will result. If you're using an active pigment, backruns will appear just from capillary action at the upper edge of a stationary wash bead. If you're using heavy pigments, the bead quickly collects the largest and darkest pigment particles. These backruns or pigment stripes will show up very clearly when the wash has dried even though they may not be apparent while the wash is still wet. Finally, the action of brushing in alternating directions can be awkward to manage with one hand, especially with a flat brush.
horizontal wash brushstrokes
top: full width horizontal brushstroke; bottom: refreshed horizontal brushstroke
The scalloped brushstroke (right) solves these problems by creating an irregular, broken pattern to the wash strokes, freeing the artist to add new paint randomly over the entire surface of the wash. Each scallop creates its own small wash bead at the bottom of the curved stroke, and this bead is picked up by the new stroke coming underneath it, so the timing and flow of the wash application can be adjusted with great flexibility and accuracy. Just make a new scalloped stroke anywhere along the irregular bottom edge of the wash, to add paint or move a bead that has been resting for too long.
Lay this stroke down in a graceful, light, movement don't daub or dither with it. The shape of the stroke should not be mechanical, but varied to fit the location and shape of the specific wash area you paint. Mechanical repetition creates a regular pattern, which is easier for the eye to detect.
The scalloped stroke lets you control banding, brushstroke edges and backruns with greater freedom. You can start with the wash bead of a stroke, pull it downwards, then back up into another bead nearby, combining two beads into one. Or you can start below one wash bead, pull downwards to make a new bottom edge, then brush upwards into a second wash bead to dislodge any heavy pigment particles. You can make the lower edge sharply curved, to create a focused wash bead, or nearly flat, to spread the wash bead across a larger edge. In short, you can fit the stroke to the situation, and solve problems the moment you see them appear.
If banding occurs in the scalloped wash beads across the wash area, the irregular shape and placement of these bands will make them much less noticeable and create a subtle textural variation that blends well into the overall watercolor effect.
cerulean blue washes
painted with straight (left) and scalloped (right) brushstrokes
The example shows the difference between these two strokes for a robustly granulating pigment, M. Graham cerulean blue (PB36). The banding on the left shows the straight brushstroke at its very worst: but the scalloped stroke solves the banding problem completely.
If you must paint against very complex or detailed edges, the scalloped strokes allow you to break these maneuvers into small segments, independent of the overall accumulation of the wash. You can paint part of an edge, quickly refresh any wash beads that have gathered for too long, paint another increment of edge, and so on, giving you much greater control over the overall movement of the wash.
scalloped wash brushstrokes
Finally, the crossed brushstroke (right) is the most aggressive. The paint is laid down with short, overlapping strokes, and except for the strokes at the top of the page, the start of each stroke crosses over the end of a previous stroke. The brush is used almost with a scrubbing emphasis, so that any collection of heavy pigment particles that may have formed is dispersed by the new stroke.
The strokes can be crossed with either an upwards or downwards direction; the diagram shows downward strokes, which are safest to use only when the painting surface is nearly flat. However, this stroke is useful for heavily granulating pigments, and (as discussed in the section on tilting), these are painting with very little tilt anyway.
Very coarse pigments, such as cerulean blue or manganese blue, may require this kind of aggressive brushing to smooth out irregularities in pigment density at the start and end of a single wash stroke, and to break up bands that form within the wash beads. If necessary, you can go back into an area of the wash that you've already laid down (to add paint or smooth out visible brushstrokes), because heavy pigments tend to backrun very little when new pigment or water is added to them.
The crossed brushstroke is also useful in painting graded washes, as it can pull the darker wash mixture downward much more effectively than the scalloped or straight strokes, which rely only on the flow of the wash bead.
Complex Cutouts. By this time you should have guessed that you can use pretty much any application method or combination of brushstrokes, provided that you (1) control backruns, (2) efface brushmarks and (3) obtain even paint distribution. You fit the application to the problem.
Complex cutouts require technical flexibility. Most washes necessitate a "cutout" at the edges painting around the edge of a differently colored area. Clouds or a city skyline against the sky, or the background behind an object, are common challenges. The normal procedure is either to use a straight brushstroke which you break and then continue on either side of the foreground form(s), or scalloped brushstrokes to take the wash first down one side of the form, then down the other side.
Botanical painters are familiar with even more complex situations, where the upward and outward radiation of stems and flowers produce many separate, narrowing spaces.
The example shown below is a recreational painting (unretouched) that I knocked off in a few hours because I enjoyed looking at the subject. The problem here was to get a homogenous background behind the weave of stems and petals. I wanted to use an active pigment (phthalo turquoise), but the paper was relatively absorbent which minimized the problem of backruns.
I could not get a horizontal stroke across all the detail edges before the start of the stroke had dried to a hard edge; scrubbing out the edge would leave a backrun. I could have turned the paper sideways, effectively painting left to right down the sheet, to reduce the length of each horizontal stroke, but decided that wouldn't be much easier. I did not want to go to the utter fuss of reserving all the botanical detail with a liquid resist, especially as i wanted to paint it freehand (without an underdrawing).
wash sequence around complex shapes
a still life watercolor (top) and the strategy used to paint the background (bottom)
Instead I (1) simplified the design, (2) painted in all the botanical detail first, and then (3) painted the background sequentially with the paper laid flat, as shown above with arrows and numbers.
The design was simplified by carrying a few stems to the paper edge, as shown by the white dots. These cut the background into four detached areas (not counting the peekthrough areas around the vase handle). Each of these areas could be painted independently of the others.
I started with an upward path (1) that let me practice the petal cutouts early on, then carried this over the top of a bordering stem (2). I painted outward and downward along a gradually expanding edge (3), and when the paint reached the opposite stem I painted first down (4) while lightly rewetting the edge along (5), then across the remaining area to the corner. I carried this edge around the second stem and repeated the strategy into the next area (6,7). This completed the first background section and I stopped for a rest. Other sections were completed in the same way, and I finished by filling in the leftover peek through areas (16).
This strategy works because at every spot where I had to negotiate detail cutouts, the stem patterns left me with only a few inches of wash bead to keep wet and moving forward. With the paper laid flat the "bead" is really the wettest paint edge, but as long as this edge is kept moving at a constant rate with even paint application, backruns will not usually form, even in active pigments. That is, I painted without the wash bead because I didn't need it to get color homogeneity.
The crux is that it is normal to increase pressure on the brush during detail painting, to improve control; but this also reduces the paint flow onto the paper and produces uneven color and minor backruns. With a small paint edge to control there was no panic imperative to keep working quickly, which left me more time to paint the detail cutouts with care, and ensure even paint application.
to wet or not to wet
The final wash nuance is whether or not to prewet the wash area or the paper as a whole. Some artists first sponge or brush the area with water and let it dry completely. Others wet the area in the same way, then lay in the wash while the surface has a shiny to satin wetness. Still others paint the wash directly on dry paper.
Prewetting as Surface Preparation. Many artists habitually prewet a wash area, or the entire paper surface, as a way to minimize or eliminate contaminants on the paper surface that can destroy an otherwise smooth wash texture.
There are two types of problems. The first is fine pinholing tiny white flecks that appear in a wash after it has dried. The second, related problem is unsightly large whitish splotches that appear immediately after a wash has been applied.
Both these problems seem to occur most often on block sheets, but I have also encountered them on supposedly high quality individual sheets from large manufacturers. The usual causes in both cases are impurities such as oils on the paper surface or a somewhat thick layer of gelatin tub sizing that has collected in the paper depressions and will repel paint until it is dissolved.
Both problems can be prevented by prewetting the entire paper with pure water or with a highly diluted gum arabic solution, then quickly and lightly "polishing" the paper surface with an acrylic flat brush or large sponge in a gentle, rapid, scrubbing or polishing motion. After this brief cleaning, hang the paper vertically until it is completely dry. Do this before you begin to draw or paint on the sheet.
This treatment dissolves away any surface impurities, breaks up the dried skin of tub sizing on the paper, and also slightly raises the nap of the compacted cellulose fibers, making the surface more absorbent. If you do not want to disturb the surface texture (especially in a hot pressed sheet), you can identify large problem areas by first flooding the paper surface with water, then immediately holding the sheet vertically by one corner to drain the water away. The entire sheet should dry in even gradations of wetness from top to bottom: any areas that will repel a wash become visible as prematurely "dry" patches on the surface. These should be treated as described above.
Tiny pinholing usually occurs in paints made with dark valued, finely divided pigments with a low pigment to vehicle ratio typically this includes the phthalos, quinacridones, iron blue, dioxazine violet and carbon black. These require extra attention as you paint. Paints made with a high pigment to vehicle ratio (cadmiums and iron oxide pigments) or large particle size (cobalts) are less affected, but can still show this problem in diluted solutions.
crossed wash brushstrokes
A partial remedy is to use a stiffer wash brush and to pull the brush more slowly across the paper. If pinholes appear while the paint is still completely wet, go back into the area with the brush and a little more paint and use a circular, scrubbing motion to work the paint into the imperfections. Don't do this if the paint has partly dried, as you will create blossoms or backruns. If the pinholes appear long after the paint has been applied then the only remedy is a second coat of paint.
But keep in mind: anything that happens while you paint can be used for expressive effect. If you can learn to produce pinholing at will through your choice of paint and paper, you can use it to produce a glittery visual texture in a dark color area.
Prewetting for Paint Blending. Prewetting the surface is also a simple method to improve the evenness of the wash. It obscures brushmarks and prolongs the wash drying time, so it is an obvious help for pigments that dry quickly or have a tendency to streak (the heavy pigments in particular). Prewetting also encourages different colored paints to blend, which is especially useful in a graded wash, where extra time is especially valuable and a smooth mixture (between paint and clear water, or two different colors of paint) is hard to achieve. Prewetting is also advantageous when painting around complex edges, as the longer drying time gives you more time to paint accurately.
Prewetting is awkward when the painting surface must be tilted (that is, for active pigments), as the wash bead will not form on the wet surface the brush strokes immediately start to diffuse down the page. For these pigments, prewetting and then applying the paint in a level wash is best. Also, prewetting gives pigments of very different textures more time to separate on the paper. If you mix a wash with a cobalt and quinacridone pigment, a prewetted application will give the quinacridone more incentive to separate and blossom away from the cobalt, producing more interesting blossoming and two color effects. Of course, these become more spectacular when the separate pigments are very different colors from their mixture for example, when you apply a violet mixed from a dark magenta quinacridone and a light cobalt teal blue.
Whenever possible, I prefer to prewet the wash area with brush and water, just as if I were applying the actual wash. I use water that is very lightly tinted with the wash solution or a harmonizing color, so that I can see where the paper is still dry. This prewetting lets me practice the overall wash strategy, assess the timing of the wash application, and recognize any difficulties created by complex edges. If I stumble into a problem with the wash application, or discover that water is evaporating too quickly, or locate a splotchy patch on the paper surface, I find this out with an almost invisible tint of water instead of an irreversible layer of paint. This prewetting will make the paper more receptive to the wash layers whether or not you let the paper dry.
I wet approximately around complex edges, not actually up against them. It's always harder to paint a complex edge twice rather than once, and if I prewet beyond the edge by mistake, then I must let the area completely dry before I can apply the paint. So I save the one time for the actual paint. If the edge area is dry, but the area near it is moist, then the prewetting actually helps to wick paint toward the edge as it dries, making a crisp and slightly darkened border around the wash area.
Some artists use special wash additives in order to manipulate the drying time or viscosity of a wash solution. These preparations require carefully adjusted concentrations of pigment in the mixture, and the use of paint additives such as ox gall, glycerin, or alcohol. I've also experimented with adding a little glycerin soap to the wash solution, to break the water tension.
I urge you to experiment with these additives to learn their effects. I excluded them from my own methods on the grounds that I did not want additional equipment (chemicals) as part of my wash technique, and because my limited experiments with these additives did not show me that they added anything essential.
So: we've divided up the wash into its separate components and examined each in turn. Now we can put these back together in wash practice, using whatever combination of methods is appropriate to get a specific result.
The Level Wash. In this method you lay the paper perfectly flat to start. Using whatever brushstrokes are convenient, you cover the area to be washed with paint to a shiny wetness. If areas of the wash begin to dry before you have finished, rewet them with a moderately wet brush. When the entire wash area is covered to an equal wetness, quickly and lightly brush over the entire area as needed to ensure smooth coverage, then wick off with a brush any puddles of water in the wash or around the edges. Let sit undisturbed until dry.
This wash covers the paper with a good dark color and slightly uneven texture and that's the main point of a level wash. Heavy pigments can be smoothed out nicely with the brush to create a somewhat random, feathery texture. Active pigments, such as prussian blue or ivory black, tend to show subtle backruns and streaking as well. But all wash applications, brushed out or not, will show slight variations in surface pattern.
These texture variations largely follow the patterns in which the wash area was painted: the last painted areas are the wettest, so they will backrun into the earlier painted areas, which have already started to dry. By varying the amount of wash solution painted down at the start and finish, and by choosing the start and finish of the wash and the sequence of areas painted in between, you can control the pattern of the backruns without adding more water. (Painting the wash in one pass, using the minimum amount of wash liquid, and not going back to rewet areas that begin to dry too quickly will increase these random variations.) This is a spontaneous approach that lets the water play a natural role in the finished effect, with surprisingly lyrical results.
The level wash also interacts strongly with the paper surface. Papers that are heavily sized and therefore relatively unabsorbent, or thin papers or papers that have already been wetted and have cockled, will cause pooling or puddles in the wash. These create areas of darker color and also areas at the center of expanding backruns. If a large amount of liquid accumulates in the pools, the dried pigment can show impressively complex, random variations in pigment color and density.
The Tilted Wash. This is the commonly recommended approach. You begin the wash with the paper tilted to a small angle, and apply the paint to dry paper from top to bottom of the wash area. You normally use a straight or scalloped stroke, and pull the wash bead downwards as you go. Finish off with strokes that do not add more paint, so that you use up what remains of the wash bead in the bottom of the wash area. Let sit until dry, using a moist, thirsty brush to wick off any excess paint that beads at the bottom edge.
For the majority of watercolor paints, this method works fine. You can adjust the force of gravity on the water by changing the tilt of the board: below a 10% slope there is very little pull, and above 25% the pull is very strong. As described above, you use a higher tilt primarily to inhibit backruns in lighter than average pigments, or when using a large brush that applies a large amount of liquid in one stroke.
The Two Step Wash. This method combines the two previous approaches and can be very effective, especially for active and heavy pigments.
The paper is laid perfectly level to start, and the wash area is filled in completely with paint using a scalloped or crossed brushstroke. Sufficient wash liquid is used to bring the paper to a soaked wetness.
Once all brushing is done, tilt the surface up very slightly (about 5°), and use a moist brush (shaken out, or wicked on a paper towel) to draw off the excess liquid at the bottom. When the downward flow of paint at this tilt begins to slow, tilt the paper slightly higher to keep the water moving. Wick off excess paint as it forms a bead along the bottom edges. Continue increasing the tilt and wicking off the excess until the wash area has stabilized or the paper is tilted vertically. Let stand undisturbed to dry, and continue to wicking off any excess that collects along the bottom edge.
The two step wash is the only method that can suppress irregularities in very active pigments, yet can be manipulated to produce subtle or strong variations in wash texture with heavy pigments. The surface is extremely even and consistent, with one exception: a darker band of concentrated pigment may form along the bottom edge of the wash area.
You can suppress this darker band by using less paint, by tilting the surface more slowly as it dries (this requires some practice, to keep backruns from forming!), or by carrying the bottom edge of the wash entirely off the painted area, onto the stretching tape or the paint board. I find it is also possible to lighten this band by wicking directly from it, rather than from the edge of the paper but this is a little risky, as the wicking can cause backruns.
three washes of iron (prussian) blue
scalloped brushstrokes with level (left), tilted (center) and
The example shows these three techniques used with the same brush, paper and Daniel Smith iron blue (prussian blue, PB27) wash solution. An active pigment, iron blue will backrun slightly if capillary movement is not controlled; it also contains visible grains, which will cause banding in a tilted wash with straight brushstrokes. Using a scalloped stroke, all the wash techniques get good results: the level wash technique gives the richest color with subtle and expressive variations in paint density, while the two step method gets a really impressive flatness and a perfectly random distribution in the darkest, heaviest particles (note also the dark band at the bottom).
Graded Wash Techniques. In the graded wash, the objective is to create a gradient in the hue or value of the color area. Most often this means an even transition between a full strength mixture and a transparent wash (pure water), but it can also be a transition from one color to another.
This is the most difficult wash effect to do correctly, and it verges on the impossible if you must also manage complex edges or cutouts as you work. Don't get discouraged, though: practice will bring you familiarity with the common problems and how to deal with them.
One approach is to build the gradient through two or more wash applications, so that the imperfections in each wash average out. I find that this often only invites disaster several times instead of once; in particular, it is hard to paint complex edges exactly the same across all the different washes.
The other approach is to reserve the whites with tape or resist, and then paint one or more wash gradients with abandon. Once the washes have dried, remove the resists, and you have crisp, perfect edges. To my eye, the edges created by resists look contrived and artsy, and resists and tape are a major addition in equipment and fuss. They also tend to make the finished paintings appear mechanical.
With experience, you'll also discover design points that make the finished result more acceptable. For example, if the wash gradient is exactly parallel with vertical, any deviation from a perfect gradient shows up with exasperating clarity. If you tilt the gradient slightly to one side or the other, for example in imitation of late afternoon light or a slanted shadow across a wall, then a missed gradient is along the diagonal, and appears as part of the overall textural variations in the painting.
Dry Gradient Wash. In this approach, the paper is dry, and either tilted or laid flat to start. If tilted, use a moderately steep angle (15% to 30%) to enhance the blurring of the gradient across wash strokes. Orient the paper so that the dark area of the wash is at the top and the light (clear) area is at the bottom: the line of flow of the water down the page must be parallel with the line of the gradient.
Start at the top with a single straight stroke of pure wash solution on dry paper, mixed to a darker color than you need. Now, dip the end of the brush tuft lightly in the rinse water, and lift it out without stirring or shaking it. When it has stopped dripping, apply the mixture of wash solution and water to the paper, again using a straight stroke back and forth, pulling the bead of pure wash mixture downwards. Overlap the strokes more than you normally would on a straight stroke up to half with width of the brush. Dip the brush again, but this time farther up the tuft; apply the second stroke. On the third dip, shake the brush slightly in the rinse water, lift it out and let drain, then paint.
Bring more rinse water in successive strokes, shaking the brush more aggressively each time you dip, until you're bringing clear water at the end of the wash. Always use alternating or back and forth strokes, so that the paint and water are well mixed as you move down the page.
You can leave the wash in position, either flat or tilted, or tilt it upwards from flat position, in the two step approach. This will enhance the blurring of the gradient by increased downward flow of the water. To do this, you need to manage very cleverly the amount of liquid on the surface: too much liquid at the top or sides will flow down the page in uneven rivulets or curtains, marring the effect. I can only get this to work by starting flat, then increasing the tilt as I go (and as the wash mixture becomes more diluted); this drains the water down before puddles can form.
The challenge is getting the successive mixtures of paint and rinse water in the right concentrations to make an even gradient from the darkness you want to the lightness you want. You are pulling the bead of pure wash mixture down with each stroke, so you have to balance the strength of this mixture by the amount of water you add with the brush; yet you can't shift gears quickly to pure water, as this will create a sharp change in the gradient. You also have to pace the mixture change differently, depending on the size of the wash area. Practice will teach you how to manage the added water.
When the wash is at a satin or moist wetness, you can go back up into the wash and brush on more wash mixture if the gradient is not changing fast enough, or to smooth out visible brushstrokes. If you try this when the wash is at a shiny wetness, you'll create a backrun.
You must get the moisture of your brush just right, neither too wet (it will leave a blossom or backrun in the wash area) nor too dry (it will soak up paint, leaving a light mark). This is not hard to adjust: at the right moistness the brush will leave light, drybrush like marks that dry immediately on dry test paper. In the wash, apply the brush very lightly to leave soft, feathery strokes that resemble the marks of chalk or pencil. These marks will not backrun, yet will diffuse just enough to disappear.
Prewetted Gradient Wash. This proceeds exactly as for the dry gradient wash, except that the wash area has been prewetted with clear water. This eliminates the wash bead, so that paint diffuses freely down the paper as you work, and blends the brush strokes more quickly.
The downward flow of paint makes the gradient more even down the page, but as a drawback it also makes it easy to run the dark values too far down the wash area, and does not give you a wash bead to work with. As a result, the flat or two step wash methods work best for a prewetted gradient wash: the change from one color to another is adjusted before water is allowed to move.
Because the paper is already wet, you need to reduce the amount of liquid you bring to the page on each stroke. This somewhat defeats the purpose of prewetting the page in the first place, since these less juicy strokes are less likely to blend evenly. A different kind of balancing act: and one that judicious brushing with a moist brush will help to get just right.
Brushed Gradient Wash. This approach throws pride to the wind and works the wash downward with explicit brushstrokes, just as if you were painting in oil or acrylic. Scalloped or crossed brushstrokes are best, working flat or tilted, on prewetted paper. This method works best with heavy pigments.
Starting flat, first use the prewetted method to get the wash basically in shape top to bottom, tilting the surface slightly upwards in the two step method as you work, and finishing with a tilt at around 15%. Add extra pure pigment at the top of the wash if it should be darker, or wipe away pigment at the bottom if it needs to be lighter, and finish by wicking up excess liquid.
Then use a large, completely dry wash or hake brush to stroke very gently the surface of the wash to smooth out any irregularities or blemishes. The surface must have a satin wetness, and a slow drying time from satin to moist. A wash area at satin to moist wetness is most responsive to a soft dry brush, and can produce very subtle color changes across a large value range.
single color graded washes
ultramarine blue painted with dry (left), prewetted (center) and brushed (right) technique; all painted with scalloped brushstrokes
The figure shows three washes done with these three gradient techniques, using the same brush, paper and Daniel Smith ultramarine blue (PB29) wash mixture. Note the tendency of the dry wash to transition too soon into a light value, and the tendency of the prewet method to transition too late. A few more years of practice, and I'll get them right.
Rex Brandt proposed a fiendishly rigorous test for the single color graded wash. Paint the righthand two thirds of a watercolor paper with a graded wash, top to bottom, and let dry. Then turn the paper 180°, and paint the same wash again on the (new) righthand two thirds. These two washes overlap in the middle third of the paper, but their gradients go in opposite directions. If both washes are graded exactly the same, this central section will be a perfectly flat color. Some day when you're feeling especially sure of your wash technique, try it!
Multiple Wash Layers. The final variation is to lay multiple wash solutions over the same area. This is unavoidable if you are painting multicolor gradients: a blue sky shading down to a yellow haze along the horizon (which fades gradually back up into the blue sky). Each wash is painted separately, with whatever technique seems appropriate.
This approach produces especially luminous clear skies, and also luminous dark areas such as hills and shaded undergrowth. John Sell Cotman used multiple washes to great effect (though his were usually not graded, but flat), laying down successively darker layers of the same color to get luminous, rich darks.
The main caution is to let the previous wash dry completely before starting the next wash. Especially bad things happen when you lay a wash over a previous wash that is still at a moist or damp wetness. The paper will look dry, but the moisture under the surface can erupt in backruns, uneven diffusion, broken wash beads, muddy pigment mixtures, and other ghastly surprises.
basic wash principles
My approach to the watercolor wash has been to break it down into its separate components, examine how each component affects the painting outcome, and then reassemble them into flexible wash strategies. Along the way I've uncovered some basic wash principles that you won't find anywhere else. Here they are:
Work as slowly as possible. Despite the common advice that you should work quickly, there is never any benefit in working as fast as you can. Just the opposite is true: you want to paint as slowly and serenely as possible, given your materials and objectives. The only constant is to keep the wash bead moving downward in a way that prevents brushmarks, pigment deposits and backruns. But how quickly you must move it depends on the tilt, the brush, the wash mixture, the heat and humidity, the absorbency of the paper, and other factors. If you can adjust any of these components to give yourself more time to complete the wash, there is almost never a reason not to do so.
Tilt no more than necessary. As a general rule, tilt the paper only enough to get the benefits of gravity flow without any of the drawbacks. The tilt most appropriate for a painting depends on specific factors the size of the wash area (the importance of flawless color), the time it will take to complete, the number of complex or precise cutouts around or inside the wash, the type of paints in the wash mixture, its dilution with water, the size and type of brush you are using, the surface texture and absorbency of the paper, even the humidity and temperature. Don't hesitate to change the tilt as you work. When in doubt, practice on a smaller piece of used watercolor paper.
Study pigment and paint mixtures. Almost all the difficulties in wash technique tiny pinholes, wash banding, streaky or visible brushstrokes, blossoms or backruns come down to the behavior of the paint solution, which means the pigment in the paint. You can almost always mix the same wash "color" with many different combinations of paints, and each combination will have benefits or drawbacks in terms of how the wash is applied. At the outset, think about which pigment mixture you want to use, and why. This is a topic you will only understand with experience: keep painting, learn how your materials behave, and discover what works best for you.
Pick the safest method. There is always more than one technique different tilt, different brush, different wash strategy to paint a wash to get the same wash effect. If the results are the same, choose the method that you can do most confidently or that creates the least risk of accident or failure in the execution.
Consider multiple washes. You will have to use multiple washes in order to glaze one pigment over another, but you can also lay multiple layers of the same pigment to produce more even, homogenous results. The main constraints here are the complexity of the wash edges (which are harder to do cleanly if they must be done more than once), and the eagerness of the wash already applied to dissolve under a new coating of liquid.
Visualize before you paint. Athletes know the benefit of visualization before performing in a competitive sport. This can also help with wash technique once you start, you won't really have time to step back and consider your progress, and you'll forget the qualities of color or light that you found so interesting in the landscape. Begin by looking at the motif and visualizing your wash against it, exactly as if you were painting over a transparent sheet of paper. Visualize the brushstrokes, the pigment intensity, the wash flow, the edge painting. Locate the areas of light, dark, and color change. Continue the visualization from the first stroke of the brush to the last bead of the paint. Repeat several times, if necessary. Then, look down at your paper, and begin!
Improvise!. Don't lose sight of the fact that you can change and modify washes in midstream. You can change the tilt, the brushstroke, the dilution of the paint, the wetness of the paper; you can go back in with a dry brush and touch up uneven areas; you can add water to create expressive blossoms or backruns; you can blot water with a towel or let it run. Once you have mastered the separate elements of the wash, you'll discover an amazing freedom to improvise rather than slog mechanically through a routine procedure.
The final guidance applies to everything in painting: practice, practice and more practice. If the only time you paint a wash is when you are doing a painting that you care about, then the consequences of failure are higher. Because major paintings take longer to complete, you also have fewer opportunities to paint a wash, so you learn more slowly. The solution is to play with washes by practicing basic exercises to learn how to do them better. Rex Brandt painted washes around names or words written in fat white block letters in the middle of the page: painting around these complex curves and straights, while keeping the wash moving down the page, is a great challenge to your dexterity and sense of timing. You can also use drawn silhouettes of clouds or trees, or an urban skyline, to keep the exercises more practical. Experiment with washes when you paint sketches: a mistake here is not so serious. Use scrap paper (the back of discarded paintings for example) to practice as often as possible.
I've found that there is always more to learn about doing a good wash. It's rare that I do a wash that I feel could not have been done better. It's a genuine test of skill, and a very satisfying achievement.
Rex Brandt's test of