Hansa yellow G PY1 is a marginally lightfast, opaque, staining, very light valued, intense yellow pigment, offered by more than 40 chemical pigment manufacturers worldwide. PY1 is one of many pigments where the ASTM and independent lightfastness tests diverge: the ASTM (1999) rates it as having "very poor" lightfastness (V), but my own tests put it in category III ("fair"), with a tendency to darken in masstone and fade in tints. These differences are possibly due to variations in the quality of the pigments tested by the ASTM and used by Lukas and Blockx. The average CIECAM J,a,b values for hansa yellow G (PY1) are: 84, 1, 70, with chroma of 70 (estimated hue purity of 55) and a hue angle of 89.

The Blockx yellow and Lukas helio genuine yellow light were both a cheerful sunny color, unresponsive to rewetting or wet in wet application, closely resembling most cadmium yellows (PY35).

AVOID. The arylides are (with the cadmiums and benzimidazolones) one of the three major types of yellow pigment. However PY1 is less expensive and clearly less lightfast than other arylides, and is appropriate only for student grade or school paints. Many other yellow pigments have a similar color, and most are more transparent in watercolors, so there is no reason to use this impermanent and opaque product. Choose a cadmium yellow (PY35) or benzimida yellow (PY154) instead.

lightfastness test samples

unexposed (left); exposed 800+ hours (right) — Blockx, Lukas

 Hansa yellow light PY3 is a marginally lightfast, semitransparent, moderately staining, very light valued, intense green yellow pigment, offered by almost 50 pigment manufacturers worldwide. The average CIECAM J,a,b values for hansa yellow light (PY3) are: 88, -12, 72, with chroma of 73 (estimated hue purity of 58) and a hue angle of 99.

The ASTM (1999) rates its lightfastness in watercolors as "very good" (II), but my 2004 tests suggest this may be true of some paints but is not true for all. The full strength color in most brands began to darken (brown) slightly after about 6 weeks to two months of sunlight exposure (BWS 6); in some brands this discoloration was significant. Frequently the tints faded noticeably.

hansa yellow light lightfastness samples (2004)

after 800+ hours of sunlight exposure: (left to right) Utrecht, Sennelier, Daniel Smith, Schmincke, DaVinci

In watercolors PY3 undergoes a very small drying shift, darkening slightly and losing less than 5% saturation. The color and texture are equivalent across the different paint manufacturers, but brand formulations affect the lightfastness, transparency, staining, saturation and reactiveness wet in wet (which is usually sluggish). Typically, PY3 is slightly more intense than a cadmium lemon of the same hue, because the cadmium paint is slightly lighter valued. PY3 is a good choice for a "primary" yellow paint if you want the palette to lean toward green; otherwise choose a neutral yellow such as hansa yellow (PY97) or benzimidazolone yellow (PY154). PY3 is the greenest synthetic organic yellow available in watercolors, and is popular with paint manufacturers, particularly in student grade paints and green convenience mixtures (it creates brilliant yellow greens when mixed with the green phthalos, and interesting tan oranges, close to burnt sienna, when mixed with quinacridone rose, PV19).

The brands shown in the samples above are the most lightfast among the paints tested. All show discoloration in the masstone color, except for Sennelier, which fades somewhat more in tints. Daniel Smith hansa yellow light is slightly less green than the other lemon yellow paints and is more heavily staining, but has noticeably higher tinting strength in mixtures and in a tinting test, and is more transparent and saturated than the other paints listed here. The Utrecht paint is the most transparent but is also less concentrated, and therefore less saturated. The DaVinci paint is one of the most lightfast but also the most opaque and least saturated, with a light valued, chalky appearance. The Art Spectrum paint darkened in masstone after a few weeks of sunlight exposure. Holbein's paint is a clever imitation of aureolin that is more lightfast than PY40 but also less transparent.

CAUTION. I found significant differences in the sunstruck pigment color across the various watercolor brands in both the full strength and tint samples. To be sure of the paint you use, I suggest you do your own lightfastness test, both on pure pigment paints and on any convenience green paints made with PY3. See also the section on monoazo pigments.

Chrome yellow PY34 is an impermanent, semiopaque, heavily staining, very light valued, intense yellow pigment, in hue most similar to hansa yellow medium. Formerly a widely used industrial pigment, it is offered in a very wide range of formulations by 20 pigment manufacturers, mostly for use in metallic coatings, ceramics and plastics; its use is declining because it contains lead, a polluting and toxic heavy metal. Note that the ASTM watercolor tests (1999) gave the chrome yellows an "excellent" (I) lightfastness rating, while my 2004 tests put the Winsor & Newton paints in category IV ("poor"): the chroma faded by more than 20%.

AVOID. To my knowledge, chrome yellow paints have been discontinued in art materials available the USA and Europe (my Winsor & Newton samples were retrieved from a retailer's discontinued inventory), but you should avoid them if they reappear. Brighter and more reliable yellow pigments are available at lower cost. The deep yellow hue most resembles a cadmium yellow (PY35), but is noticeably duller (browner); the lemon yellow resembles zirconium praesodymium silicate (PY159). Both are superior pigment alternatives.

TOP 40 PIGMENT  Cadmium yellows (the reddish PY37, made of pure cadmium sulfide, and the greenish PY35, compounded with zinc sulfide) are semiopaque, staining, very light valued, intense green yellow and yellow to light valued, intense orange yellow and yellow orange pigments. The average CIECAM J,a,b values for the hue categories listed above are: (1) cadmium yellow lemon: 89, -10, 71, chroma 72 (estimated hue purity 57) hue angle 98; (2) cadmium yellow pale: 86, -4, 77, chroma 77 (estimated hue purity 61) hue angle 93; (3) cadmium yellow light: 86, -2, 77, chroma 77 (estimated hue purity 60) hue angle 91; (4) cadmium yellow: 81, 11, 78, chroma 78 (estimated hue purity 60) hue angle 82; (5) cadmium yellow deep: 71, 34, 68, chroma 77 (estimated hue purity 57) hue angle 63.

Generally the cadmiums are very lightfast, but in random instances can be impermanent (see examples and comments below). Genuine cadmium [zinc] sulfide is available from 10 registered pigment manufacturers worldwide; only one manufacturer offers cadmium coprecipitated with barium sulfate (lithopone). The ASTM (1999) requires cadmium lithopone to be labeled "PY35:1" or "PY37:1" if it contains 15% or more of barium sulfate, as Daniel Smith has done. In watercolors PY35/37 undergoes a very small to moderate drying shift, depending on hue: all shades darken slightly, with a loss in saturation of 2% (lemon yellow) to 15% (deep yellow). (Note that loss of saturation has a greater impact in yellow colors, due to the apparent change in hue from orange to brown or yellow to green.) High quality, pure cadmium sulfide is completely permanent, covers very well, is easy to handle, moderately active wet in wet, and blossoms readily if rewetted while still moist (although it is relatively resistant to water discoloration once it has dried). It has a powdery luster on the paper, and dilutes down to glowing, near transparent tints. The cadmiums are (with the arylides and benzimidazolones) one of the three major types of yellow pigment in artists' paints. Although it has always been among the most expensive pigments since the yellow hue was discovered and commercially introduced in the mid 19th century (the orange and red hues were introduced around 1910), a continuous decline in the relative cost of the pigment has made cadmium yellow one of the most commonly used watercolor pigments. Some paint manufacturers or regulatory agencies may impose a health warning on this paint as it contains a poisonous metal (cadmium); but see my skeptical comments under health & environmental issues.

The ASTM (1999) rates the lightfastness of PY35 and PY37 in watercolors as "excellent" (I), and most independent tests agree. In my 2004 tests, which allowed for heat and humidity from outdoor sunlight exposure, I encountered an extreme blackish darkening in some hues from some manufacturers, which appeared within a few weeks of sunlight exposure and is therefore easy to detect.

discoloration in cadmium yellow lightfastness samples (2004)

after 800+ hours of sunlight exposure: (left to right) DaVinci medium, Maimeri light, Maimeri lemon, Rowney Artists medium, Grumbacher light

Note that the darkening does not appear in all hues from the same brand, and therefore seems limited to specific pigment lots. I assume this discoloration is caused by chemical impurities left in the pigment by the pigment manufacturer. (Cadmium watercolor paints can darken if exposed to excessive heat and moisture, or if lead compounds or residual free sulfur have not been washed from the pigment after manufacture.) So despite the widely repeated conventional wisdom that cadmium pigments are totally lightfast, I recommend you make your own lightfastness tests on the brands you use.

Cadmium hues can be precisely adjusted by the proportion of zinc sulfide or cadmium sulfoselenide in the pigment blend, and this allows manufacturers to choose their own placement and spacing of hues in the cadmium yellows they offer. (This cadmium color key shows the major brand variations.) Paint manufacturers customarily sample this hue range by offering two to four cadmium yellow colors: (1) lemon yellow, with a hue angle around 90 to 95, (2) pale yellow, with a hue angle around 90, (3) medium yellow, with a hue angle around 80, and (4) deep yellow, with a hue angle less than 70. However, the "pale" hue is frequently omitted (leaving three yellows), and the term "light" is used inconsistently to mean a "lemon," "pale" or even "medium" hue, in contrast to a medium or deep hue. The value and saturation depend on the hue: a good quality cadmium middle yellow is (along with hansa yellow, PY97) the most intense yellow paint available, with a chroma that in some brands can exceed 99 (average chroma 96), while cadmium yellow deep (chroma 92) and lemon (chroma 93) are always less intense. As with all warm hues, even slight differences in the lightness or value of a paint will affect the apparent saturation and hue. Hue also affects the apparent size of the drying shift: cadmium lemon or light will shift little in chroma or lightness as it dries, while the medium and deep yellow cadmium can shift to a surprising degree. Most major brands (Winsor & Newton, Daniel Smith and Holbein in particular) space the hues well; the hue spacing seems to me less desirable in MaimeriBlu or Rowney Artists. Incidentally, most artists will locate the transition from a "warm" to a "cool" yellow at around a hue angle of 85 to 90, so an all purpose "primary" yellow will be within that range.

As a group, the M. Graham, Rowney Artists, Utrecht and Winsor & Newton cadmium yellows are all comparably saturated, though M. Graham and Winsor & Newton colors tend to be slightly darker, warmer and more intense. All are staining, semitransparent to semiopaque when dried, blossom slightly wet in wet, and provide nice sheen in thin washes. Rowney Artists cadmiums are relatively transparent, inert, and staining, with a bright tone: much of what you get is apparently a transparent brightener (making the paint less opaque), and the masstone lightfastness is poor in the "light" yellow paint. The two Utrecht cadmiums seem slightly chalky to me, and are badly spaced: the "light" is really a middle hue, and the "deep" is actually orange, not deep yellow. MaimeriBlu and Daniel Smith cadmiums are less intense, semiopaque to opaque, and tend to bronze slightly when applied full strength. Blockx cadmiums are thick, semiopaque to opaque, darker than most brands, and also bronze heavily at full strength.

Within the three common hue categories, starting with a lemon yellow, Holbein cadmium yellow lemon and Rembrandt cadmium yellow lemon have the greenest hue, indistinguishable from a hansa yellow light (PY3). However, these greenish lemon yellows are also very light valued, and their whitish color has a lower chroma than other brands. The Winsor & Newton cadmium lemon is slightly warmer but also more saturated. (As always, do not choose paints on chroma or color appearance alone, but on the quality and range of colors they mix with other paints.) For the middle yellow, M. Graham cadmium yellow is a beautiful middle hue, slightly warmer than other brands. The Daniel Smith paint is slightly cooler, the Winsor & Newton noticeably warmer, mixed with a touch of cadmium orange (PO20) that creates a subtle hue shift toward orange in masstone. The hue of Rembrandt cadmium yellow light, at hue angle 88, is very close to the psychological unique yellow (as described in the section on color vision) or a neutral "primary" yellow. However, Winsor & Newton cadmium yellow pale may be a better "primary" yellow choice, as it is a slightly warmer yellow and very intense (chroma of 99), which makes it a good mixer with blues and greens. For a deep yellow paint, Rowney Artists cadmium yellow deep is an average deep hue, to my eye poised on the boundary between yellow and orange, with the best saturation and transparency. The MaimeriBlu and Utrecht may be too warm, but worth considering as a "cadmium orange light."

Cadmium yellow is among the most commonly and enthusiastically used yellow pigments. Its radiant color, tinting strength and powdery texture make it a joy to use, once you learn to adjust the mixtures to avoid bronzing and excessive opacity. If a strong yellow is important to your palette, it's worth the expense to experiment with a "middle" or "pale" ("primary") cadmium yellow to see if the pigment works for you; if it does, sample the "lemon/light" and "deep" paints to find the brands and hue spacing you prefer. Cadmiums are especially affected by dark, strongly tinting pigments such as phthalocyanine greens or blues, and some artists dislike this effect: I enjoy the velvety blends that result. These mixtures can appear dull if darkened too far, and cadmium mixtures must always be applied confidently, in a single brushstroke without any fussing or reworking, otherwise a dingy color will result. Cadmiums also dissolve quickly and densely charge a wet brush, which means you can waste a lot of paint in your rinse water if don't wick your brush before rinsing. Finally, cadmium paints may be toxic if swallowed or inhaled (for example, while spraying the paint); cadmium lithopone is less dangerous, though as a matter of record any toxic effects from using cadmium paints are highly unlikely. This means the major drawback to cadmium is price, and if that is a consideration then M. Graham or Rembrandt are probably the best value overall for color appearance and lightfastness; Winsor & Newton and Daniel Smith, though more expensive, are also generally reliable paints, and the Holbein cadmiums are beautiful but now among the most expensive. See also the section on cadmium pigments.

 Aureolin (cobalt yellow or potassium cobaltinitrite) PY40 is an impermanent, transparent, lightly staining, light valued, intense yellow pigment, made in two grades by the only registered manufacturer worldwide (Johnson Matthey, UK). The average CIECAM J,a,b values for aureolin (PY40) are: 77, 2, 69, with chroma of 69 (estimated hue purity of 54) and a hue angle of 88.

The ASTM (1999) rates its lightfastness in watercolors as "very good" (II), and Winsor & Newton's lightfastness ratings are also high. My lightfastness tests across several manufacturers suggest it deserves at best a "fair" (III) rating, as even the most durable paints (Rembrandt, Rowney and Sennelier) developed a displeasing gray cast after a few weeks of direct sunlight exposure.

cobalt yellow lightfastness samples (2004)

after 800+ hours of sunlight exposure: (left to right) Rembrandt, Rowney, Daniel Smith, Sennelier, Winsor & Newton

Aureolin has been an infrequently used light yellow since it was first introduced in 1861 by Winsor & Newton. It was marketed as a replacement for both natural gamboge (NY24) and indian yellow (a common alternative name for aureolin in the late 19th century) and its transparency produces some radiant glazing effects, but its high cost and dubious permanency limited its use. It has in turn been replaced in most watercolor paint lines because it turns gray or brown under exposure to moisture or light, or if incompletely washed of impurities after manufacture. It also requires slow processing to fully stabilize with the paint vehicle or it will expand in (and sometimes burst open) a paint tube. Winsor & Newton and Daniel Smith aureolin are the warmest, most saturated and most transparent of the aureolins listed here, and they acquire a grayish yellow and subtle granularity when applied full strength. The Rembrandt and Rowney Artists paints are significantly duller, more opaque and staining than the other brands, and the Sennelier aureolin is semiopaque, light valued and rather dense; but they are marginally more lightfast. (Holbein's "aureolin" hue is mixed from hansa yellow light and yellow ochre, listed under PY3.)

AVOID. Aureolin (like alizarin crimson) is a pigment that modern chemistry has made superfluous. There are many excellent yellows available with better lightfastness. The authoritative article by Maura Cornman (in Artists' Pigments: A Handbook of Their History and Characteristics, ed. Robert Fuller, 1986) observes that "Experimentation over the years has indicated that cobalt yellow is given to apparently capricious reactions. Thus, the evidence in the literature concerning its permanence is contradictory — some reports suggest it is extremely stable while others indicate it may turn brown on exposure [to light].... Today it is generally considered to be a relatively unstable pigment." In watercolors, the chemical purity of the pigment and any manufacturing additives may affect the pigment's behavior; however my lightfastness tests did not eliminate the effects of heat and moisture, which can affect the color significantly. Substitutions. The same radiant transparent yellow is available with excellent lightfastness in nickel azomethine yellow (PY150), which can be paired with nickel dioxine yellow (PY153) or isoindolinone yellow (PY110) as a deep yellow. The arylide hansa yellow medium (PY97) is a lovely alternative and can be as transparent as aureolin and with better lightfastness. See also the section on cobalt pigments.

Lead antimoniate or antimony yellow (PY41) is the traditional basis of genuine naples yellow, manufactured as a pigment since at least the 1400's, though similar antimony yellows appear in the middle east as early as 500 BCE. It is still offered by 3 chemical pigment manufacturers worldwide as a colorant for ceramics and glassware. The tone can vary from a light valued dull greenish yellow to a dull pinkish orange (according to Ralph Mayer), so some manufacturers (such as MaimeriBlu) offer two versions; the pinkish brown hue is more common. Most of these convenience mixtures show a moderate drying shift, actually increasing in saturation as the white pigment becomes slightly more transparent. — To my knowledge no commercially available art materials use the highly toxic PY41 pigment, but imitate it with a mixture of chinese white, cadmium yellow or red, and an iron oxide yellow or brown. Unfortunately this combination of ingredients frequently turns out to be impermanent, apparently because the zinc white degrades the mixture. (See the caution regarding the lightfastness of white pigment mixtures at PW4.)

Among the more permanent paints, the Rowney Artists is pinkish brown, close to a stereotypical premixed flesh tone; the Holbein naples yellow is a semitransparent, creamy light yellow; and the Holbein jaune brilliant #2 is a whitish red orange that shifts toward yellow in undertone, a moderately dull imitation of the pinkish hue of naples yellow (the name is a historical synonym for naples yellow). The less permanent paints include Winsor & Newton naples yellow, a lovely approximation to the original semiopaque, brownish yellow tone, but regrettably the masstone color fades somewhat to white. The Daniel Smith naples yellow is a more assertive, darker orange color, but also whitens in masstone after moderate light exposure. The MaimeriBlu naples yellow light is a semiopaque, greenish yellow shade, which also fades fairly quickly.

Naples yellow is a great convenience pigment for landscapes (mediterranean scenes, deserts, sandy beaches). To me, it's too chalky to make a convincing flesh mixture, even in tints, but some artists find it useful. Perhaps because of the lightfastness problems described here, several paintmakers have opted to use the yellow orange and naturally whitened chrome titanate (PBr24) as the substitute pigment. Clearly, given the variety in paints marketed as naples yellow, you'll have to experiment to see which version you prefer. See also the section on lead pigments.

lightfastness test samples

unexposed (left); exposed 800+ hours (right) — Daniel Smith, Maimeri, Winsor & Newton

 Nickel titanate PY53 is a very lightfast, semiopaque, staining, very light valued, moderately dull yellow pigment that can be either a pale middle yellow (hue angle around 85) or pale lemon yellow (hue angle around 95), depending on formulation or manufacturer (11 chemical manufacturers offer the pigment worldwide). The ASTM (1999) rates its lightfastness in watercolors as "excellent" (I), and my 2004 tests agree, although in some brands the paint becomes slightly more opaque in masstone after about 6 weeks of sunlight exposure. PY53 undergoes a very small drying shift, darkening very slightly. The average CIECAM J,a,b values for nickel titanate yellow (PY53) are: 85, -2, 46, with chroma of 46 (estimated hue purity of 36) and a hue angle of 92.

Winsor & Newton nickel titanium yellow, the only paint I know that used the middle yellow hue, has been discontinued. The Winsor & Newton lemon yellow is the darkest valued of the "lemon" hued paints but still has a pastel olive hue; as with all nickel titanate lemons, it appears slightly gray when viewed obliquely under strong light. Daniel Smith nickel titanate yellow and Rowney Artists nickel titanate yellow are equally chromatic, slightly lighter valued, semitransparent and less staining; either one is a good choice. MaimeriBlu is light valued but with a more opaque, weaker color. — PY53 resembles aureolin's soft yellow hue and its tendency to dull in masstone. It is a relatively weak pigment in tints and has moderate mixing strength with other paints, but creates wonderful pastel greens, browns and blues; and mixed with a touch of burnt sienna, it makes an interesting naples yellow. This is my preferred light yellow pigment for an earth palette. See also the section on titanium pigments.

Diarylide yellow deep PY55 is a very fugitive, semitransparent, heavily staining, light valued, very intense yellow orange pigment. Unrated by the ASTM (1999), my own tests put it in the "poor" (IV) category. I could only find the pigment in a convenience mixture from Holbein, where it adds chroma to the more lightfast nickel titanate.

AVOID. This mixture is unacceptably fugitive, and the same hue with similar color intensity and much better lightfastness is available by using hansa yellow deep (PY65) or nickel dioxine yellow (PY153). See also the section on monoazo pigments.

lightfastness test samples

unexposed (top); exposed 800+ hours (bottom) — Holbein

 Hansa yellow deep PY65 is a very lightfast, semitransparent, heavily staining, light valued, intense orange yellow pigment, available from 10 pigment manufacturers worldwide. It's one of the more widely used synthetic organic alternatives to cadmium yellow deep; you'll recognize the hue, which is close to color point 2 on the color wheel, because it's used to paint the yellow lines on streets and highways. The ASTM (1999) rates its lightfastness in watercolors as "very good" (II), but my own tests consistently put it in the "excellent" (I) category. In watercolors PY65 undergoes a small drying shift, darkening slightly and losing about 14% in saturation. The average CIECAM J,a,b values for hansa yellow deep (PY65) are: 77, 24, 75, with chroma of 78 (estimated hue purity of 58) and a hue angle of 72.

This pigment is very consistent across manufacturers, and has the highest chroma (saturation) of any deep yellow paint — at or above 96 (cadmium yellow deep averages around 93). Daniel Smith and Winsor & Newton hansa yellow deep are identical semitransparent, staining pigments. The Utrecht paint by contrast is nonstaining. All are inert wet in wet, but blossom readily when rewetted. — One rarely sees PY65 used in artists' palettes: the hue is a little too orange to be preferred over a middle yellow, and although it is slightly less opaque than cadmium yellow deep, it is not as strong in mixtures. Isoindoline yellow (PY110) has a nearly identical hue and may be a superior pigment for lightfastness, transparency, and lyrical color shifts. See also the section on monoazo pigments.

Arylide yellow PY74 is a lightfast to impermanent, semiopaque, moderately staining, light valued, intense yellow pigment, available from 9 pigment manufacturers worldwide for a wide range of industrial applications. It is unrated by the ASTM and I have not conducted any lightfastness testing on it. See also the section on monoazo (arylide) pigments.

Diarylide yellow HR PY83 is a lightfast to impermanent, semiopaque, moderately staining, light valued, intense orange yellow pigment, available from 50 pigment manufacturers worldwide for a wide range of industrial applications. Unrated by the ASTM, my tests put it in the "excellent" (I) lightfastness category, with a slight tendency to darken in masstone. It is a beautiful pigment, very close in hue to PY65, slightly less orange than nickel dioxine yellow (PY153), and noticeably duochrome, shifting toward a middle yellow in undertone. — Old Holland scheveningen yellow deep is apparently the only commercial source as a single pigment paint. Holbein indian yellow enhances the duochrome effect with the addition of another arylide yellow, creating one of the lightest (and least lightfast) "indian yellows" available. See also the section on disazo pigments.

lightfastness test samples

unexposed (top); exposed 800+ hours (bottom) — Holbein

 Hansa yellow PY97 is a lightfast, semitransparent, staining, very light valued, intense yellow pigment, available from 9 pigment manufacturers worldwide. The ASTM (1999) rates its lightfastness in watercolors as "very good" (II) pending retesting; my 2004 tests rate it "very good" (II) with substantial loss of color in tints in some brands but little or no color change in masstone.

In watercolors PY97 undergoes a small drying shift, holding its value but losing about 10% saturation. It deepens toward orange in masstone, approaching the hue of PY1. It is very frequently used in convenience green mixtures, because it holds its own when mixed with a wide range of other paints: it has very good tinting strength, and consistently has the highest chroma (saturation) of any yellow paint, at or above 99 (cadmium yellow medium, which is also very bright, averages around 97). The average CIECAM J,a,b values for hansa yellow (PY97) are: 85, -2, 80, with chroma of 80 (estimated hue purity of 63) and a hue angle of 91.

Daniel Smith hansa yellow medium is slightly lighter, more intense and more transparent than other brands, and is also one of the most lightfast paints, making it the marginally better choice for a versatile middle yellow. It darkens more toward orange in masstone, a lyrical quality I like. The MaimeriBlu primary yellow is lighter, greener and less staining than the others. The MaimeriBlu permanent green yellowish has the same hue angle as a nickel titanate yellow (PY53), but has a more obvious greenish hue because it is more intense. — PY97 is a good choice for a "transparent bright yellow" (the cadmiums providing an "opaque bright yellow" and the less intense pigments, such as quinacridone deep gold PO49 or nickel azo yellow PY150, providing a "transparent muted yellow"). Hansa yellow is a good general purpose yellow paint, bright enough for botanical or floral palettes, and an intense but less expensive alternative to cadmium paints for those concerned about cadmium's cost or toxicity (for example, in paints for children). See also the section on monoazo pigments.

lightfastness test samples

unexposed (left); exposed 800+ hours (right) — Winsor & Newton, Daniel Smith, Maimeri

Anthrapyrimidine yellow PY108 is a lightfast, semiopaque, moderately staining, light valued, moderately intense orange yellow pigment, a laked pigment made from vat dyes, available from only 2 pigment manufacturers worldwide. Unrated by the ASTM, my own tests put it in the "very good" (II) category, with a slight darkening and reddening appearing in masstone after about 6 weeks (BWS 6), and slight fading in tints. It is two toned, showing a dark almost ochre yellow in masstone and a summery, subdued yellow in tints. The paints tested here were moderately active wet in wet, and blossomed readily. The average CIECAM J,a,b values for anthrapyrimidine yellow (PY108) are: 72, 14, 65, with chroma of 67 (estimated hue purity of 52) and a hue angle of 78.

Schmincke has the name right, since their version of PY108 is a very close match to the original gamboge pigment (as formerly manufactured by Winsor & Newton). But Daniel Smith indian yellow is the color I'd recommend: more lightfast, more transparent and less staining, with a warmer, brighter hue in masstone and a larger undertone hue shift toward yellow.

CAUTION. This is a beautiful muted yellow but its discoloration in the Schmincke version suggests you do your own lightfastness test. In general, unsaturated azo yellows such as PY108 or the more lightfast nickel azo yellow (PY150) mix more pleasing landscape greens with green or blue pigments, and their duotone character makes them very versatile for botanical illustration. Well worth trying out as an alternative to yellow ochre or raw sienna (PY42/43). See also the section on anthraquinone pigments.

lightfastness test samples

unexposed (left); exposed 800+ hours (right) — Daniel Smith; Schmincke

TOP 40 PIGMENT Isoindolinone yellow R PY110 is a lightfast, transparent, moderately staining, light valued, intense yellow orange pigment, available from 6 pigment manufacturers worldwide. The ASTM (1999) rates this isoindoline yellow as having "excellent" (I) lightfastness; manufacturer and industry tests agree. My 2004 tests suggest it may be the most lightfast deep yellow pigment available. In watercolors PY110 undergoes a small drying shift, losing about 10% saturation. The average CIECAM J,a,b values for isoindolinone yellow (PY110) are: 72, 34, 68, with chroma of 76 (estimated hue purity of 60) and a hue angle of 63.

M. Graham gamboge was the first source of the pure pigment in watercolors, which was discontinued in 2001 for a "gamboge" made with a PY151+PO62 mixture; in 2007 Daniel Smith came into the market with their permanent yellow deep, and thereafter M. Graham brought the pigment back into their line. The paint has a slightly dark, glowing, yellow orange color, with a gorgeous chroma, but in tints it calms toward an ochre; it is relatively inactive wet in wet but blossoms when rewetted.

PY110 is a beautiful warm yellow, with a hue between hansa yellow deep (PY65) and benzimida orange (PO62), but it is more transparent, slightly darker valued, somewhat more active wet in wet, and with a larger hue shift toward yellow in tints. It provides superior landscape green mixtures with both green or blue paints. For those concerned with paint lightfastness, toxicity and transparency, PY110 may be the optimal choice for a deep yellow paint, superior even to nickel dioxine yellow PY153. See also the section on isoindolinone pigments.

Copper azomethine green (PY117), commonly but not always the ingredient in a "green gold" paint, is an impermanent, semitransparent, staining, mid valued, moderately intense yellow pigment, available from only 3 registered pigment manufacturers worldwide. Unrated by the ASTM, manufacturer tests rate it as having "very good" to "excellent" (I) lightfastness, but my lightfastness tests revealed poor lightfastness in the Holbein paint, the only source for this pigment in commercial watercolors. The hue is midway between PY129 and PG10, slightly darker valued and more textured than PY129. The average CIECAM J,a,b values for green gold (PY117) are: 58, -1, 60, with chroma of 60 (estimated hue purity of 51) and a hue angle of 91.

For more information, see under PY129, below.

AVOID. As this pigment is impermanent and easily matched by other pigments, there is no reason to use this paint. See also the section on metal complex pigments.

lightfastness test sample

unexposed (top); exposed 800+ hours (bottom) — Holbein

Benzimidazolone yellow PY120 is an impermanent, semitransparent, staining, light valued, intense yellow pigment, available from only 2 chemical pigment manufacturers worldwide. Unrated by the ASTM, my 2004 tests put it in lightfastness category III ("fair"), which makes it unsuitable for artist's materials. It has a hue resembling hansa yellow (PY97) or a middle cadmium yellow (PY35), but it turns toward a toasty nut brown after moderate exposure to light (this is surprising, given the generally excellent lightfastness of benzimidazolone pigments). The average CIECAM J,a,b values for benzimidiazolone yellow (PY120) are: 80, 8, 75, with chroma of 75 (estimated hue purity of 59) and a hue angle of 84.

Old Holland scheveningen yellow medium is apparently the only commercial watercolor source; the paint is active wet in wet and resists blossoming.

AVOID. As this pigment is impermanent and easily matched by other pigments (see above), there is no reason to use this paint. See also the section on benzimidazolone pigments.

lightfastness test samples

unexposed (top); exposed 800+ hours (bottom)

TOP 40 PIGMENT Copper azomethine green (PY129), commonly the ingredient in "green gold" paints, is a lightfast, semitransparent, staining, mid valued, moderately dull yellow to green yellow pigment, available from only 3 registered pigment manufacturers worldwide. Unrated by the ASTM, manufacturer tests rate it as having "very good" to "excellent" (I) lightfastness, and my lightfastness tests agree. In watercolors this "green gold" pigment undergoes a moderately large drying shift, holding lightness but losing saturation by up to 30%; in tints the color shifts from yellow green into a beuatiful light yellow. This pigment is related to other copper (PG10) or nickel (PY150) azomethines, other forms of metal complex pigment. The average CIECAM J,a,b values for green gold (PY129) are: 53, 4, 49, with chroma of 49 (estimated hue purity of 46) and a hue angle of 86.

Winsor & Newton green gold is the yellowest of the azomethines and (with M. Graham) the most saturated, with a beautiful slight granulation in masstone or wet applications. The paint shifts slightly further toward green and becomes more chromatic in tints. Old Holland is slightly darker and lifts more readily. — "Green gold" copper azomethine is a delightful and extremely useful category of pigment for all genres, but for landscape and botanical painting especially. The M.Graham and Stephen Quiller paint brands have recently added it to their inventory, and Robert Doak sells an especially brilliant form as a liquid watercolor paint. Copper azomethine has a high tinting strength in mixtures, and can produce beautifully transparent and brilliant yellow greens when mixed with a green phthalocyanine, moody and luxurious sap greens when mixed with iron blue, and a gorgeous range of botanical tans and ochres, and portrait flesh tones, when mixed with quinacridone magenta. Copper azomethine is useful as a glazing pigment to mute or warm other colors; it works very well to brighten and shift to yellow all green pigments, even the cobalts. And if you are an avocate of the split "primary" palette, then copper azomethine is the perfect lightfast, transparent "cool yellow" pigment to pair with its lightfast, transparent "warm yellow" twin, nickel azomethine yellow (PY150).

CAUTION. Most green golds have very good lightfastness, but you should specifically avoid the Holbein paint, which (given its impermanence) may not be an azomethine pigment at all but a phthalocyanine/arylide convenience mixture. (The Colour Index (4th edition online) currently shows no manufacturers registered for PY117.) Any green gold paint you use should first be tested for lightfastness. See also the section on metal complex pigments.

Quinophthalone yellow PY138 is a lightfast, semitransparent, staining, very light valued, intense yellow pigment, available from just 2 pigment manufacturers worldwide. It has a hue resembling cadmium yellow (PY35) or hansa yellow (PY97). The ASTM (1999) rates it as having "very good" lightfastness (II), and my own tests show a slight lightening of the pigment after two months of daily sunlight exposure. — Rowney permanent yellow is apparently the only commercial source; the paint is active wet in wet and resists blossoming. — A lovely basic yellow color, in a relatively new category of synthetic organic pigment. Possible alternative to the arylide hansa yellow (PY97) or benzimidazolone yellow (PY154) in the same hue category.

Isoindoline yellow PY139 is a very lightfast, semitransparent, moderately staining, light valued, intense yellow orange pigment, available from 4 pigment manufacturers worldwide. The hue is closest to a cadmium or hansa yellow deep. Unrated by the ASTM, my tests found it has "excellent" (I) lightfastness, with very slight fading in tints. The CIECAM J,a,b values for isoindolinone yellow deep (PY139) are: 72, 35, 68, with chroma of 77 (estimated hue purity of 61) and a hue angle of 63.

MaimeriBlu is currently the only manufacturer to use this pigment; their formulations are very active wet in wet and blossom when rewetted. MaimeriBlu permanent yellow is a very orangish, dark yellow; the MaimeriBlu indian yellow is less intense with a slight brownish cast. — The pure pigment paint is worth investigating if you want a transparent warm yellow for your palette (it is almost exactly the same hue and value as Daniel Smith cadmium yellow deep). The "indian" convenience mixture is to me flat and solid, not as attractive as nickel dioxine yellow (PY153) but very predictable in mixtures. Both paints are very lightfast. See also the section on isoindolinone pigments.

TOP 40 PIGMENT  Nickel azomethine yellow PY150 is a very lightfast, transparent, moderately staining, nongranulating, moderately light valued, moderately intense orange yellow pigment, available from 3 pigment manufacturers worldwide. The ASTM (1999) rates its lightfastness in watercolors as "excellent" (I); my own and manufacturer tests agree. In watercolors PY150 shows a small drying shift, holding its lightness but losing about 15% saturation. An apt name for PY150 might be "new gamboge deep", as it has the same two toned appearance: in masstone it is a dull deep yellow (chroma of around 65) very similar to genuine gamboge (NY24); in tints it rises to a sunny, noticeably cooler and more intense (chroma 75) middle yellow. The average CIECAM J,a,b values for nickel azo yellow (PY150) are: 67, 14, 61, with chroma of 62 (estimated hue purity of 49) and a hue angle of 77.

Some paint manufacturers or regulatory agencies may impose a health warning on this paint as it contains a heavy metal (nickel); but see my skeptical comments under health & environmental issues.

Both Winsor & Newton transparent yellow and Daniel Smith nickel azo yellow are rather dark, warm and subdued in masstone, but rise to a wonderfully glowing middle to light yellow in tints; the Schmincke paint is lighter and cooler in masstone and makes a smaller undertone hue shift toward middle yellow, both indications of a lower pigment concentration in the paint formulation (and lower tinting strength). All paints blossom moderately and are among the most transparent yellows available.

The metal azomethines comprise a small and very interesting but underutilized group of pigments that may (very unfortunately) be gradually disappearing from pigment manufacturer offerings. However, the recent discontinuation of quinacridone gold (PO49) may motivate the use of PY150 as a replacement, for example by Winsor & Newton. PY150 seems to me to be a superb botanical yellow. Applied full strength, it is a yellow just on the border of brown, and makes a beautiful series of vegetable yellows, oranges and reds when mixed with a dull red or dark red violet paint. Mixed with a phthalo green, nickel azo yellow creates beautifully varied, natural yellow greens resembling the color of spring leaves and new lawns. (It works very well with most blues, too: try it in particular with iron blue [PB27] to get an excellent "hooker's green".) And in tints it is a gentle floral yellow, close in hue to aureolin, the hue of many varieties of flowers. Overall, I strongly recommend you try it. See also the section on metal complex pigments.

lightfastness test sample

unexposed (top); exposed 800+ hours (bottom) — Schmincke

Benzimidazolone yellow PY151 is a very lightfast, semitransparent, staining, very light valued, intense yellow pigment, available from 9 pigment manufacturers worldwide. Unrated by the ASTM, my tests assign it "excellent" (I) lightfastness. Even though its saturation is high, the light yellow hue position means it can easily take on a slightly brownish cast. In watercolors PY151 undergoes a very small drying shift, barely shifting in lightness or saturation. The average CIECAM J,a,b values for benzimidazolone yellow (PY151) are: 84, -1, 75, with chroma of 75 (estimated hue purity of 59) and a hue angle of 91.

M. Graham azo yellow (aureolin) is a very good "primary" yellow, leaning neither to red nor to green, with a bright, clear appearance. It is very active wet in wet and blossoms readily. The Schmincke paint is warmer, and although it is as saturated as the M. Graham paint this hue difference gives it a slight brownish cast. It is also semiopaque and bronzes when applied full strength. Both paints are good mixers and remain bright in tints. — The benzimidazolones are (with the cadmiums and arylides) one of the three major types of artists' yellow pigment. Confusingly, the "azo" is often pulled from the "benzimidazolone" as a generic nickname, though "azo" equally applies to a very large family of yellow, orange and red synthetic organic pigments. (Paint manufacturers are quite certain that artists are incapable of accepting "benzimidazolone" in paint names, though DaVinci's "benzimida" works for me.) This pigment closely resembles benzimidazolone yellow H3G (PY154), and either of them works well as a hue replacement for aureolin (PY40). See also the section on benzimidazolone pigments.

TOP 40 PIGMENT  Nickel dioxine yellow PY153 is a very lightfast, semitransparent, lightly staining, nongranulating, light valued, intense orange yellow pigment. First produced as paliotol yellow by BASF, it is now available from only 3 pigment manufacturers worldwide. The ASTM (1999) rates its lightfastness in watercolors as "very good" (II), but both manufacturer and my tests rate it "excellent" (I). In watercolors PY153 undergoes a very small drying shift, barely shifting in lightness or saturation. Most of the formulations blossom readily and are moderately active wet in wet. The average CIECAM J,a,b values for nickel dioxine yellow (PY153) are: 71, 29, 69, with chroma of 74 (estimated hue purity of 55) and a hue angle of 67.

Daniel Smith new gamboge and Winsor & Newton new gamboge are both warm, duochrome pigments; the Daniel Smith is more transparent and less staining and has the edge in color warmth. Both verge on a radiant yellowish orange in masstone. Rowney's and Utrecht's are only slightly darker and less saturated, but this makes a noticeable (attractive) difference in the apparent hue; Utrecht is the least staining and most transparent. The Sennelier paint is somewhat dull and homogenous. The convenience pigment Winsor & Newton indian yellow is quite a bit more orange and more monochrome than the original gamboge pigment (NY24), and it stains strongly.

PY153 seems most often named after the historical pigments indian yellow (described under magnesium pigments) or gamboge (NY24). Neither historical pigment has anything to do with (or much resembles) the modern color category, which varies across manufacturers from an intense yellow orange to a slightly brownish deep yellow. In any case, PY153 is a splendid deep yellow pigment from almost every point of view. Though typically not as strongly tinting or textural in mixtures as cadmium yellow deep, its transparency, versatility and hue shifts (in the darker brands) make it one of the most evocative and effective yellow pigments you will find. See also the section on metal complex pigments.

NOTE: Manufacturing of this pigment was discontinued and supplies ran out in 2012. Both Winsor & Newton and Daniel Smith have reformulated their new gamboge paints without it. I recommend any of the orange yellow or yellow orange pigments to replace it, especially PY35, PY65 and PY110.

TOP 40 PIGMENT  Benzimidazolone yellow PY154 is a very lightfast, semitransparent, staining, very light valued, intense yellow pigment, available from 4 chemical pigment manufacturers worldwide. The ASTM (1999), manufacturer and my own tests rate its lightfastness in watercolors as "excellent" (I). In watercolors PY154 shows almost no drying shift. — Offered by four watercolor manufacturers, this (or PY151) is an excellent "primary" yellow pigment, leaning neither toward orange nor green, although the undertone does shift noticeably toward green. The average CIECAM J,a,b values for benzimidazolone yellow (PY154) are: 83, 1, 77, with chroma of 77 (estimated hue purity of 60) and a hue angle of 89.

Winsor & Newton winsor yellow is a clear, bright yellow color. With a hue angle of 87, it is very close to the psychological unique yellow, as defined in the section on color vision. The Sennelier is warmer, darker, and slightly chalky. — PY154 is one of the most widely used benzimidazolone pigments. As a group, the benzimidazolone yellows seem not to be preferred in artists' palettes to the cadmium yellows (which are more opaque and more intense in tints) or the less expensive arylide (hansa) yellows, I think primarily because the benzimidazolones are relatively newer and unfamiliar pigments. However, they have good tinting strength when compared with many other pigments, and produce rather crisp, vivid mixtures with the phthalo blues and greens. Well worth trying out as a basic yellow paint. See also the section on benzimidazolone pigments.

Zirconium praesodymium silicate PY159 is a semitransparent, staining, light valued, dull yellow pigment, manufactured by BASF (Germany) and Heraeus as a ceramics colorant (Sicocer F Yellow) for wall, floor and bath tiles, and sold to the artist's trade by Kremer Pigments. Unrated by the ASTM or by me, chemistry and prior use plausibly puts it in the "excellent" (I) lightfastness category. — Winsor & Newton lemon yellow deep is the only source of this pigment in commercial watercolor paints. It is a pale, muted yellow, with an intrinsic whiteness similar to nickel titanate (PY53), which it apparently replaces in the brand color range. The name "praesodymium yellow" refers to a similar metallic oxide containing the atomic element praesodymium (Pr).

Benzimidazolone lemon PY175 is a lightfast, semitransparent, staining, very light valued, moderately intense green yellow pigment, available from only 2 registered pigment manufacturers worldwide. Unrated by the ASTM, my own and manufacturer tests put it in the "excellent" (I) lightfastness category. In watercolors PY175 undergoes a very small drying shift, barely changing in lightness or saturation. The average CIECAM J,a,b values for benzimidazolone lemon (PY175) are: 83, -8, 64, with chroma of 65 (estimated hue purity of 51) and a hue angle of 97.

Winsor & Newton winsor lemon gives the more intense, clearer tone; the MaimeriBlu is slightly chalky and noticeably less saturated. — Like some brands of quinacridone gold, PY175 has an unpleasant tendency to gum up and thicken mixtures (holding brushstrokes visibly on the paper). It is also weak in cool mixtures (with phthalo green or phthalo blue), and because it is lighter but less saturated than other yellows, it produces rather bland, artificial looking greens. I don't like it for those reasons. Because it is more lightfast, it should be preferred to hansa yellow light (PY3) if a lemon yellow paint is required; it also lacks the unpredictable quality lapses of cadmium yellows. See also the section on benzimidazolone pigments.

 Bismuth yellow PY184 is a lightfast, semiopaque, staining, very light valued, intense green yellow pigment, offered by 8 chemical pigment manufacturers worldwide. Unrated by the ASTM, my own and manufacturer tests put it in the "excellent" (I) lightfastness category, with a single fugitive exception. In watercolors PY184 undergoes a very small drying shift, barely shifting in lightness and saturation. It is almost indistinguishable from Holbein or MaimeriBlu cadmium lemon, and is very inert with water. The average CIECAM J,a,b values for bismuth yellow (PY184) are: 87, -8, 68, with chroma of 69 (estimated hue purity of 54) and a hue angle of 97.

This is a very consistent pigment across watercolor brands. Winsor & Newton bismuth yellow is an attractive color, very bright and crisp, with a negligible hue shift toward green in undertone. The Schmincke paint is slightly more opaque. The Rembrandt paint (right) unexpectedly darkened in masstone and grayed in tint after just two weeks of daily sunlight exposure.

PY184 is one of the greenest inorganic yellows available and has very good tinting strength, even when pitted against the cool, dark phthalo greens and blues. These greens can seem unnaturally bright, but if that is your aim then this yellow will serve well. Its main drawbacks are opacity and its tendency to rinse reluctantly out of the brush, but this just means the pigment mimics the powdery texture and lightfastness of a good cadmium lemon.

lightfastness test sample

unexposed (top); exposed 800+ hours (bottom) — Rembrandt

PY216, a complex of tin, antimony, zinc and titanium oxides, is a lightfast, semiopaque, moderately staining, light valued, dull orange yellow pigment. Unrated by the ASTM and not tested by me, chemistry and pigment manufacturer tests plausibly give it "excellent" (I) lightfastness. James Turner patented the original turner's yellow (lead oxychloride) in 1781; it was a bright yellow to orange artist's pigment that was popular in the early 19th century; it was fugitive and now obsolete. — Winsor & Newton turner's yellow is the only commercial source for the metallic oxide pigment, which has roughly the same hue and lightness as nickel azomethine yellow (PY150) but with a less saturated, opaque and whitish color. I find it to be excellent as a diluted foundation tint for flesh mixtures, especially in portraits; in masstone applications it can appear chalky and dense. A recent addition to the Winsor & Newton line, it indicates a trend among art materials manufacturers to utilize the relatively new, very stable complex metallic colorants formulated for automotive and ceramics applications.

Genuine gamboge NY24, the resin of the indian garcinia tree, is an impermanent, transparent, nonstaining, light valued, moderately intense orange yellow pigment that has roughly the same hue, value and hue shifts as nickel azomethine yellow (PY150); the less lightfast anthrapyrimidine yellow (PY108) is also a close color match. The only source in watercolors was Winsor & Newton, which no longer (2005) manufactures it.

lightfastness test samples

unexposed (top); exposed 800+ hours (bottom)

yellow paints made with pigments in a different color index category

Nickel azomethine green PG10 is a lightfast, semitransparent, heavily staining, mid valued, moderately intense green yellow pigment. Unrated by the ASTM, my own tests give it a "very good" (II) lightfastness rating. This pigment is apparently no longer available to paint manufacturers and there are no pigment manufacturers registered with the Colour Index. This is regrettable, as PG10 is the brightest of the yellow green nickel azomethines, a luminous olive color shading into a greenish yellow. (The average CIECAM J,a,b values for nickel azomethine green (PG10) are: 58, -8, 55, with chroma of 56 (estimated hue purity of 47) and a hue angle of 98.) The other yellow green azomethines (PY117 and PY129) as used in art materials are darker, yellower and less intense. See also the section on metal complex pigments.

KEY TO THE PAINT RATINGS. Summarized as numbers: Tr = Transparency: 0 (very opaque) to 4 (transparent) - St = Staining: 0 (nonstaining) to 4 (heavily staining) - VR = Value Range: the value of the masstone color subtracted from the value of white paper, in steps of a 100 step value scale - Gr = Granulation: 0 (liquid texture) to 4 (granular) - Bl = Blossom: 0 (no blossom) to 4 (strong blossom) - Df = Diffusion: 0 (inert) to 4 (very active diffusion) - HA = Hue Angle in degrees of the CIELAB a*b* plane - HS = Hue Shift as the undertone hue angle minus the masstone hue angle, in degrees of the CIELAB a*b* plane - Lf = Lightfastness: 1 (very fugitive) to 8 (very lightfast) for paint in tint,full strength - Mentioned in pigment notes: Chroma: For the masstone paint on white watercolor paper. - Drying Shift: Change in masstone color appearance from a glistening wet to completely dry paint swatch, in units of lightness, chroma and hue angle in CIELAB. For more information see What the Ratings Mean.

Last revised 07.I.2015 • © 2015 Bruce MacEvoy