red
Key to the Paint Ratings
PIGMENT
C.I. NAME
PIGMENT
CHEMICAL NAME
PAINT
MARKETING NAME
MANUFACTURERCODETrStVRGrBlDfHAHSLf

NOTE: This page only includes pigments in the orange red, red and deep red (including carmine and maroon) hue categories. Violet red pigments are listed on the magenta page.

PR3beta naphthol red (1873)blockx red
[discontinued in 2008]
Blockx225235403433-33,6

Beta naphthol red PR3 is an impermanent, semiopaque, staining, dark valued, intense red pigment, offered by more than 40 pigment manufacturers worldwide and primarily used in printing inks. Unrated by the ASTM, my tests suggest it has "fair" (III) to "poor" (IV) lightfastness. — The paint tested here, Blockx blockx red, is active wet in wet and blossoms readily; a dense orange red in masstone, it shifts imperceptibly toward blue in undertone.

AVOID. PR3 is an impermanent and relatively inexpensive pigment that is not appropriate for professional artwork, as there are several more lightfast red pigments available. Substitutions: try the far more lightfast pyrrole red (PR254), pyrrole scarlet (PR255) or M. Graham naphthol red (PR112), not to mention the many cadmium paints around the same hue angle (33). See also the section on beta naphthol pigments.

lightfastness test sample

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

PR9naphthol AS red (1920)permanent red deep
[discontinued in 2005]
Lukas1097234603433-31,4

Naphthol AS scarlet PR9 is a very fugitive, semiopaque, staining, moderately dark valued, very intense red pigment, offered by more than 40 pigment manufacturers worldwide and primarily used in printing inks. The ASTM (1999) rates its lightfastness in watercolors as "fair" (III), but my 2004 tests give a "poor" (IV) rating. The CIECAM J,a,b values for naphthol scarlet (PR9) are: 44, 81, 37, with chroma of 89 (estimated hue purity of 74) and a hue angle of 25.

Apparently Lukas is the only commercial source for this pigment in watercolors. A dense orange red in masstone, it shifts toward blue in undertone.

AVOID. PR9 is a relatively inexpensive pigment that is not appropriate for professional artwork, as there are several more lightfast alternatives available. Substitutions: try the far more lightfast pyrrole red (PR254), pyrrole scarlet (PR255) or M. Graham naphthol red (PR112), not to mention the many cadmium paints around the same hue angle (33). See also the section on naphthol pigments.

lightfastness test sample

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

PR23naphthol AS carmine (1911)crimson lakeHolbein210235702226-203,6

Naphthol AS carmine PR23 is an impermanent, semitransparent, lightly staining, dark valued, moderately dull deep red pigment. Unrated by the ASTM, industry and my own lightfastness tests give it a "poor" (IV) rating. Holbein is apparently the only source for the pigment in watercolors.

AVOID. One of the many early naphthol pigments, and with poor lightfastness compared to some naphthols with a higher color index number (see for more information the note on naphthol AS pigments), this pigment has nothing to offer over more modern alternatives, such as pyrrole rubine (PR264) or benzimidazolone carmine (PR176). See also the section on naphthol pigments.

PR48beta oxynaphtholic acid scarlet (1902)scarlet lakeHolbein225234603038-131,6

BONA red PR48 is a fugitive, semiopaque, staining, moderately dark valued, intense orange red pigment. Unrated by the ASTM, industry and my own lightfastness tests give it a "poor" (IV) rating. — Holbein scarlet lake is the only commercial source I know of; this paint is inert wet in wet, but blossoms moderately when rewetted. The undertone is noticeably bluer.

AVOID. Since the late 19th century, scarlet lake has been the marketing name for several fugitive scarlet pigments or convenience mixtures. None of the historical pigments are available today in commercial paints. The label is nonspecific when applied to modern synthetic organic pigments, as several of these are laked, including PR188, PR255 and PO72, but in general these paints are semiopaque. Substitutions: the closest color match is probably naphthol scarlet (PR188) or, for even greater intensity that is correspondingly harder to handle in mixtures, the stunning disazo scarlet (PR242).

lightfastness test sample

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

PR831-, 2-dihydroxyanthraquinone lake (1868)alizarin crimsonRembrandt326425403220-52,6
PR83alizarin crimsonM. Graham010445501426-101,6
PR83alizarin crimsonDaniel Smith001436114125-101,6
PR83alizarin crimsonWinsor & Newton002435903226-131,5
PR83alizarin crimsonUtrecht147434802222-151,5
PR83alizarin crimsonRowney Artists515335901225-81,4
PR83carmine [hue]Holbein211424703222-91,4
PR83alizarin violet lakeSennelier9404255143337-21,3

 Alizarin crimson PR83 is a fugitive, transparent, staining, dark valued, moderately intense deep red pigment, offered by 5 pigment manufacturers worldwide. (The color index name "PR83" refers to a lake of the natural anthraquinone pigment, isolated from the madder root by Robiquet & Colin 1826; many manufacturers used the CI name "PR83:1" for the synthetic laked pigment invented by the German chemists Graebe and Lieberman in 1868, although this usage is not sanctioned by the Colour Index International.) The average CIECAM J,a,b values for alizarin crimson (PR83) are: 33, 70, 22, with chroma of 73 (estimated hue purity of 64) and a hue angle of 17.

Madder was used as a fabric dye in ancient Egypt and as a pigment in Roman times, and it is mentioned in some medieval painting treatises (though not as a pigment used by itself). It became one of the most important natural organic pigments in European oil easel painting in the 17th and 18th centuries; Joshua Reynolds and J.M.W. Turner used it throughout their careers. Winsor & Newton first introduced alizarin crimson in watercolors in 1891. Since then — and until recently — it has been the 19th century synthetic organic pigment most widely used by watercolor painters for a violet red or "cool red" color.

The madder extract contains two distinct dyes (fiery orange purpurin and bluish red alizarin); the color of alizarin lakes ranges from scarlet through pink and rose red to bluish red, depending on the proportions of purpurin and alizarin the formulation and the chemical — aluminum, tin, calcium, iron or chromium — that provides the inert substrate for the laking process.

As sold today, the color is consistently a dark, intense crimson when wet, and undergoes a very large drying shift (lightening and losing saturation) toward maroon). Applied as a juicy wash, some brands produce a subtle flocculation, and most brands are fairly active wet in wet (alizarin requires extensive milling to disperse in a vehicle, so a dispersant is often added to the paint batch to decrease the milling time). The alizarin crimsons by Winsor & Newton, M. Graham and Rowney Artists were the most intense of the brands listed here; Utrecht and Holbein were the dullest. The formulations by Daniel Smith, Winsor & Newton and Rowney Artists give the darkest values in masstone; Utrecht and Rembrandt are less concentrated and therefore lighter; M. Graham is close to average.

The lightfastness of alizarin crimson ranges from very poor to marginal. By modern standards, the pigment consistently fails to meet the minimum lightfastness standards expected of professional watercolor paints. The ASTM (1999) lists it in a table of pigments "not sufficiently lightfast to be used in paints" and rates its lightfastness in watercolors as "poor" (IV, PR83) or "very poor" (V, PR83 FE). And no matter who does the lightfastness testing, they always end up with results that look like this ("before" at right, "after" at left):

alizarin crimson lightfastness samples (2004)

after just 300 hours of sunlight exposure, the tints in all samples have completely faded: (left to right) Winsor & Newton, Daniel Smith, Holbein, M.Graham, Rembrandt, Rowney Artists, Sennelier

Many paint companies still offer alizarin crimson, especially those paint companies with an entrenched and backward looking customer base; and some published watercolor tutorials continue to advocate it, simply because a dwindling number of "old master" (age 50 and above) workshop and bistro gallery artists continue to use it. These folks claim to believe that alizarin is "lightfast enough" for professional quality work, or that lightfastness concerns about it are mere "nit picking and hairsplitting". A few forward looking watercolor brands (Da Vinci, Kremer, Maimeri, Robert Doak) do not use it in any paint, and the majority of up and coming watercolor painters have concluded it is unacceptably impermanent and should be replaced by a modern synthetic organic alternative. (See "Substitutions" below.)

What do the paint companies say? Daniel Smith makes over 130 watercolors, rated for lightfastness in four categories; only two paints fall in the lowest ("fugitive") category: alizarin crimson and rose madder. Schmincke makes 105 watercolors, rated for lightfastness in five categories; only one paint gets the lowest rating: alizarin crimson. Winsor & Newton makes 96 watercolors, rated for lightfastness in three categories; only two paints are in the lowest category: rose madder and alizarin crimson. The previous Grumbacher line offered 55 watercolors, rated for lightfastness in four categories; only three paints were rated in the lowest category — all made with alizarin crimson. As you see, paint manufacturers unanimously affirm that PR83 stands almost unchallenged as the least permanent pigment available in watercolors today.

The sunstruck behavior of the paint is deceiving. Both the tint and masstone color seem robust for about 4 weeks (~225 hours) of summer sunlight exposure, then the tint begins to fade rapidly over two weeks until the color is completely gone (see examples above). The masstone begins to lighten and lose saturation about a week after that, but it too becomes drastically degraded within another month. Those first four or five weeks may mislead some artists to the opinion that the published lightfastness results are inaccurate and that the pigment is "lightfast enough"; but this assumes that the painters who still use alizarin have actually tested it.

AVOID. Alizarin crimson has been tested hundreds of times since the late 19th century (when it was the preferred violet red pigment of amateur painter Queen Victoria of England), and there is simply no credible argument in its favor. I even recommend using a swatch of alizarin crimson as a homemade exposure control in lightfastness test because it fades so reliably. The argument made by some painters that no problems appear in paintings left around the studio for a year or two, or that a painter has "gotten no complaints" from buyers, is idiotic and self deluding. These painters merely reveal that they can't be bothered to test their palette choices. If they did, they would see for themselves the damage they inflict on their own work, on the good faith of their collectors, and on market confidence in the investment quality of watercolor paintings.

Substitutions: Modern chemistry has innovated several relatively lightfast replacements for traditional but fugitive crimson pigments. To understand these choices, you should approach the choice of substitutions as replacing the single alizarin crimson paint with either one, or two, lightfast alternatives.

If you want to make a one for one substitution, then there are five pigment substitutions for alizarin crimson currently offered in commercial watercolor paints: (1) benzimida carmine (PR176), (2) quinacridone pyrrolidone (PR N/A), (3) pyrrole rubine (PR264), (4) anthraquinone red (PR177, a chemical cousin of alizarin), and (5) a few relatively dark and reddish varieties of quinacridone violet (PV19). (These paints are typically offered under marketing names such as alizarin crimson hue, azo alizarin, quinacridone alizarin, permanent alizarin crimson, etc.) All these paints are semitransparent and don't lose intensity or shift to brown when they dry, making them satisfactory color alternatives for alizarin crimson. However they all have marginal lightfastness (6,7 in my tests), which is still far better than the average lightfastness of alizarin crimson (1,5).

I think the affection many painters feel for alizarin crimson actually has to do with its dullness rather than its intensity, as alizarin can mix glowing, flexible flesh tones, dusky violets and silky near blacks; these painters often feel the quinacridones are too strident and bluish. For them a two paint substitution may be more desirable. I highly recommend perylene maroon (PR179) as the best substitute for alizarin crimson. It is exceptionally lightfast for a red or carmine pigment, and provides some of the "blue red" reflectance necessary to produce dull violet mixtures with violet blue or blue paints. I am continually delighted by what I can do with it in portrait, botanical and landscape color mixtures. However a brighter violet red color will sometimes be wanted, and for that purpose I recommend choosing as a second paint either quinacridone magenta (PR122) or quinacridone rose (PV19). These two paints can also serve as single paint substitutions for alizarin crimson, to optimize mixtures with both warm (yellow, orange) and cool (blue) paints; or they can be muted as desired with perylene maroon.

PR106mercuric sulfide (c.800)vermilion [genuine]
[discontinued in 1999]
Blockx320044314135+13,3

Genuine vermilion PR106 is a fugitive, very opaque, heavily staining, moderately dark valued, intense orange red pigment. The ASTM (1999) rates its lightfastness as "fair" (III), but in my own tests, which allowed for the heat of direct sunlight, I saw its muted scarlet fade to a horrid scabby brown after just two weeks of sunlight exposure (BWS 4), earning it a "poor" (IV) rating. Mercuric sulfide is also poisonous. In addition to these dubious virtues, it is extremely expensive ($31 for a 15ml. tube in 2004).

My sample of Blockx vermilion was relatively inert wet in wet, blossomed very readily, and yielded a subtle flocculation when dry. For reference, The CIECAM J,a,b values for this genuine vermilion (PR106) were: 47, 71, 38, with chroma of 80 (estimated hue purity of 66) and a hue angle of 28.

AVOID. I bought this paint to observe its color characteristics, as many 19th century painters, including Winslow Homer and Paul Signac, used it. It is completely unsuitable today for professional artwork. Substitutions: There are many reliable modern pigments to choose from. The closest color match to the historical pigment was provided by Winsor & Newton vermilion hue (a cadmium hue mixture, now discontinued, listed below under PR108). The best color and opacity match is a cadmium scarlet or cadmium red light, or naphthol scarlet (PR188). Many paints named "vermilion," such as the Holbein [cadmium] vermilion, are much too orange. See also the section on mercuric pigments.

lightfastness test sample

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

PR108cadmium sulfoselenide (1892; 1910)cadmium scarletWinsor & Newton084234303340-38,8
PR108cadmium redWinsor & Newton082135003234-28,8
PR108cadmium red deepWinsor & Newton083245014231-28,8
PR108+PY53cadmium sulfoselenide + nickel titanate yellowvermilion hue
[discontinued in 2005]
Winsor & Newton23224411433408,8
PR108cadmium red lightM. Graham05014481313208,8
PR108cadmium redM. Graham04004531232608,8
PR108cadmium red paleRowney Artists50604451313408,8
PR108cadmium redRowney Artists50104491313108,8
PR108cadmium red deepRowney Artists50204591312508,8
PR108cadmium scarletDaVinci21314390323908,8
PR108cadmium red mediumDaVinci211144313237-48,8
PR108cadmium red deepDaVinci210145112129-38,8
PR108:1cadmium lithoponecadmium red scarlet
[discontinued in 2006]
Daniel Smith006044201137-18,8
PR108:1cadmium red
[discontinued in 2006]
Daniel Smith08214491223108,8
PR108:1cadmium red deep
[discontinued in 2006]
Daniel Smith083045612326+18,8
PR108vermilion [cadmium scarlet]Holbein218124103138-48,8
PR108cadmium red lightHolbein214024713135-18,8
PR108cadmium red deepHolbein215035112132-38,8
PR108cadmium purpleHolbein21703531203008,8
PR108cadmium scarletLukas217034210039-38,8
PR108+PO20cadmium sulfoselenidecadmium red lightRembrandt303144513137+28,8
PR108cadmium red mediumRembrandt31414481313308,8
PR108cadmium red deepRembrandt306145013130-28,8
PR108cadmium red lightMaimeriBlu226144411237-18,8
PR108cadmium red deepMaimeriBlu232035412127-18,8
PR108cadmium red lightUtrecht143234301236+38,8
PR108cadmium redUtrecht144234800131+38,8
PR108cadmium red deepUtrecht144235900125+48,8
PR108cadmium redBlockx323045213129-28,8
PR108cadmium purpleBlockx32514541102408,8

TOP 40 PIGMENT   Cadmium red PR108 is a very lightfast, opaque, staining, moderately dark valued, very intense red orange and orange red to dark valued, intense red and deep red pigment. Genuine cadmium sulfoselenide is available from 10 registered pigment manufacturers worldwide; only 2 manufacturers offer the cadmium coprecipitated with barium sulfate (cadmium lithopone). The ASTM requires cadmium lithopone to be labeled "PR108:1" if it contains 15% or more of barium sulfate, as Daniel Smith has done. In watercolors PR108 undergoes a small to moderately large drying shift, depending on hue: all colors hold their lightness well (even darkening slightly); the scarlet shades lose about 15% saturation, while the deep shades lose as much as 30% saturation. The average CIECAM J,a,b values for the hues of cadmium reds listed here are: (1) cadmium scarlet: 46, 80, 43, chroma 91 (estimated hue purity 75), hue angle 28; (2) cadmium red: 41, 78, 36, chroma 86 (estimated hue purity 71), hue angle 24; (3) cadmium red deep: 36, 73, 28, chroma 78 (estimated hue purity 66), hue angle 21.

Although it has always been one of the most expensive artists' pigments since it was discovered and commercially introduced shortly after 1910 (the yellow hue was introduced in the mid 19th century), a continuous decline in the relative cost of the pigment has made cadmium red one of the most commonly used watercolor paints.

Cadmium hues can be very precisely adjusted by the proportion of cadmium sulfoselenide in the pigment mixture; a middle red hue is composed roughly of 3 parts cadmium sulfide and 2 parts cadmium sulfoselenide, This allows paint manufacturers to adjust by mixture (and particle size) the placement and spacing of hues in the cadmium reds they offer. (This cadmium color key suggests the variations.) All commercial watercolors bracket the hue range with at least two cadmium red colors, and a few brands offer three or four cadmium reds. The marketing labels are usually: (1) cadmium red light (or scarlet), with a hue angle between 35 to 40, (2) cadmium red medium (or middle), with a hue angle between 30 to 35, and (3) cadmium red deep (or purple), with a hue angle below 30. (Most artists would place the boundary between "scarlet" and "orange" at a hue angle between 40 and 45.) Note that the span of cadmium red hues (from about hue angle 25 to 40 across all brands) is roughly one third that of the cadmium yellows (from about 60 to 100): most of the color variation of these red paints is due to changes in lightness and chroma, not in hue. The scarlet cadmiums are the lightest valued and most intense (average lightness 53, average chroma 82), while the deep cadmiums are darkest and dullest (average lightness 43, average chroma 66). As darker watercolors tend to have a larger apparent drying shift, the scarlet cadmiums shift little in chroma or lightness as they dry, while the deep cadmiums will darken and dull to a surprising degree.

The ASTM (1999) rates the lightfastness of PR108 in watercolors as "excellent" (I), and most independent tests agree. In my 2004 lightfastness tests, which allowed for normal variations in humidity and heat from outdoor sunlight exposure, I also found "excellent" (I) lightfastness in all hues and brands, which contrasts with the apparently random darkening that can affect cadmium yellow [cadmium zinc sulfide] paints. However, cadmium paints can darken or lose saturation if exposed to heat, moisture, lead compounds, or if residual free sulfur has not been washed from the pigment after manufacture (you may smell the sulfur when you work with cheap paints), so it may be prudent to do your own lightfastness tests on the brands of paint you use.

High quality, pure cadmium sulfoselenide is completely permanent, covers very well, is easy to handle, moderately active wet in wet, and blossoms readily if wetted while still moist (although it is relatively resistant to water discoloration once it has dried). It appears deceptively opaque when applied wet to the paper, but dries to a much more transparent appearance. The finished color has an irreplaceable, powdery luster in masstone, and a glowing, fleshy and transparent color in tints. The Holbein cadmiums are very saturated (except for the purple hue) and closely spaced along the spectrum. However, Winsor & Newton cadmium reds are just as saturated, staining, semitransparent, with a slight blossom wet in wet, and a nice sheen in thin washes. As a group the Winsor & Newton color locations are shifted toward orange (warmer) in comparison to the paints from other manufacturers. Daniel Smith cadmiums are slightly less intense, semiopaque to opaque, and tend to bronze when applied full strength. Within the three common hue categories, starting with a orange red, Winsor & Newton cadmium scarlet is the farthest orange of any orange red, a distinctive and very useful color, especially for figure and portrait painting. For a middle red, the Winsor & Newton cadmium red is a beautiful example, again slightly warmer than other brands. I find that the Winsor & Newton cadmium red deep is too similar to their medium red shade. For a good example of deep red, which I find especially useful in landscape painting, the M. Graham cadmium red is a great choice: semiopaque, staining, with a hue and value equivalent to MaimeriBlu or Daniel Smith red deep, but with higher saturation. (Note that M. Graham and MaimeriBlu do not offer a middle cadmium red: MaimeriBlu's "light" is a scarlet hue; M. Graham's "light" is a middle hue.) The Utrecht cadmiums are among the lightest, most transparent and softly textured, but are also less saturated than the Winsor & Newton or Holbein, and the vehicle tends to bronze when applied full strength. Blockx cadmiums are thick, semiopaque to opaque, bronze heavily at full strength, and are noticeably duller and darker than other brands. Typically the less expensive brands of cadmium (DaVinci, Lukas, Rowney Artists) have a lighter color and a somewhat whitish tone due to added brighteners.

Cadmium red is one of the most commonly and enthusiastically used red pigments. If a strong red is important to your palette, it's worth the expense to experiment with a middle or scarlet cadmium red to see if it works for you; if it does, sample the "deep" paints to find the range of hues you prefer. Cadmium tends to appear dull when mixed with dark, strongly tinting synthetic organic paints such dioxazine violet, phthalo green or phthalo blue, which some artists dislike. I enjoy the moody dark mixtures that result, but note: always test dark cadmium mixtures by painting out a sample (fine cadmium particles floats over the mixture when stirred, then sink to the bottom, making the color hard to judge), and always apply cadmium mixtures confidently, without any fussing or reworking, otherwise mud will result. Cadmiums are quick to dissolve and deeply charge a wet brush; I go through much less water if I pinch the tuft in a paper towel before rinsing it. Finally, cadmium sulfoselenide may be toxic if inhaled (for example, by spraying the paint) or swallowed; cadmium lithopone is less dangerous, though as a matter of record toxic effects from cadmium almost never occur. This means the major drawback to cadmium is price, and if that is a consideration then M. Graham, MaimeriBlu or Rembrandt are probably the best value overall for color appearance and lightfastness; Winsor & Newton and Daniel Smith, though more expensive, are very reliable paints. The Holbein cadmiums are beautiful but now among the most expensive; currency exchange rates may lower the price at certain times. See also the section on cadmium pigments.

PR112naphthol AS-D red (1911)naphthol redM. Graham120445012234-107,8
PR112permanent redHolbein021145103336-146,7

 Naphthol AS-D red PR112 is a lightfast, transparent, heavily staining, moderately dark valued, very intense orange red pigment, offered by over 30 pigment manufacturers worldwide for use in inks, plastics and cosmetics. The coloristics (lightness, hue and saturation) are almost indistinguishable from the impermanent beta naphthol scarlet (PR3) and are very close to the slightly yellower naphthol scarlet AS (PR188). The ASTM (1999) rates its lightfastness in watercolors as only "fair" (III, "may be satisfactory when used full strength or with extra protection from exposure to light"), but my 2004 tests give it a "very good" (II) rating, although there was a noticeable difference between the two brands tested here. In watercolors PR112 undergoes a very small drying shift, darkening slightly and losing saturation by about 10%. The average CIECAM J,a,b values for naphthol AS red (PR112) are: 43, 81, 42, with chroma of 91 (estimated hue purity of 75) and a hue angle of 27.

M. Graham naphthol red is gorgeous, high quality red paint: transparent, bright, moderately active wet in wet and somewhat responsive to rewetting, and throwing off a delicate texture of tiny pigment flakes in juicy washes. The Holbein paint is opaque, slightly more active wet in wet, and less lightfast.

CAUTION. This is one of several pigments where manufacturer and ASTM lightfastness tests disagree, possibly because the pigments tested were from different chemical suppliers. Many artists avoid all naphthol pigments as possibly too impermanent, and clearly the watercolor paint brand matters when the pigment is available from so many different pigment manufacturers worldwide. I suggest in these doubtful cases that you conduct your own lightfastness tests. My main objection is that these brilliant red paints are less flexible in mixtures than the perylenes or quinacridones, but when used unmixed, the rich hues are absolutely striking — many shades of lipstick attest to that! See also the section on naphthol pigments.

lightfastness test samples

unexposed (left); exposed 800+ hours (right) — M. Graham, Holbein

PR149perylene scarlet (1957)perylene scarletDaniel Smith044235413130-56,6

 Perylene scarlet PR149 is a marginally lightfast, semiopaque, staining, dark valued, intense red pigment, offered by four pigment manufacturers worldwide. Unrated by the ASTM, my 2004 lightfastness tests give it a "very good" (II) rating; masstone and tint darken and dull after two months' exposure to sunlight. The hue name is misleading: the color is actually a lovely middle red, between a cadmium red and a cadmium deep red. PR149 undergoes a moderately large drying shift, lightening by 15% and losing up to 25% saturation. The CIECAM J,a,b values for perylene scarlet (PR149) are: 35, 68, 29, with chroma of 74 (estimated hue purity of 62) and a hue angle of 23.

Apparently Daniel Smith perylene scarlet is the only commercial source. This paint is inert wet in wet, but blossoms readily when rewetted, and shows a lovely subtle flocculation in wash applications. It undergoes a strong color change as it dries, lightening in value and shifting from a lustrous deep red to a brownish red.

CAUTION. This is an evocative and lovely pigment, very flexible in mixtures, and one of my favorites when I began painting. I no longer use it because I don't really trust its lightfastness, but it is not a reckless choice. Daniel Smith gives the pigment a "very good" (II) rating, the same rating they give to naphthol red (PR170) or hansa yellow light (PY3), which some painters use without worry. I suggest you conduct your own lightfastness test. See also the section on perylene pigments.

lightfastness test sample

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

PR168anthraquinone scarlet (1913)permanent red lightMaimeriBlu251334102338-77,7
PR168old holland bright redOld Holland151314203037-67,6

Anthraqinone scarlet PR168 is a lightfast, semitransparent, staining, moderately dark valued, very intense orange red pigment, twin to anthraquinone red (PR177); only three manufacturers offer it worldwide. Unrated by the ASTM, my own and other independent tests assign it "very good" (II) lightfastness, with a slight tendency to darken in masstone. Rather light valued for a red pigment, it has a soft geranium color, blossoms easily, but thins out to a dull tint. The average CIECAM J,a,b values for anthraquinone scarlet (PR168) are: 44, 79, 39, with chroma of 88 (estimated hue purity of 73) and a hue angle of 26.

Of the two paints tested, the MaimeriBlu permanent red light is significantly more saturated (and more lightfast), and has a soft, slightly clumping texture not uncommon in less expensive laked pigments. — Recently added to Maimeri's paint line, and a relatively old laked pigment, PR168 has a unique light scarlet hue that seems useful for botanical or portrait palettes, but is less effective as a general purpose red paint.

lightfastness test sample

unexposed (top); exposed 800+ hours (bottom) — Old Holland

PR170naphthol AS carbamide F3RK (1911)permanent redDaniel Smith075245303131-86,7
PR170naphthol AS carbamide F5RK (1963)carmine [hue]Rowney Artists509244803425-125,7
PR170permanent red deepDaniel Smith093245603430-154,6
PR170dark red [crimson]Schmincke345235201224-103,5
PR170naphthol red (mid-tone)DaVinci257paint introduced after my last pigment tests

 Naphthol red AS PR170 is a marginally lightfast to impermanent, semiopaque, heavily staining, dark valued, very intense red to deep red pigment, offered by close to 40 pigment manufacturers worldwide. Often used in plastics and cosmetics, naphthol reds as a group vary widely in lightfastness. For this reason alone, some artists avoid them entirely. The ASTM (1999) gives PR170 a "very good" (II) lightfastness rating, and while most manufacturer or independent tests agree, my 2004 tests rated the pigment somewhat lower, and found the lightfastness depends on paint brand, pigment hue (the deeper reds seem less lightfast) and pigment density. (Note that PR170 actually refers to a family of several dozen monoazo pigments, denoted by the alphanumeric codes added to the color index name by some manufacturers.) In watercolors PR170 undergoes a small drying shift, losing less than 20% of its saturation. The average CIECAM J,a,b values for naphthol AS red (PR170) are: 38, 81, 30, with chroma of 86 (estimated hue purity of 73) and a hue angle of 20. All the paints tested here shifted strongly toward blue in undertone.

Daniel Smith permanent red is the warmest, lightest and most lightfast paint tested here; it is also the least active wet in wet, the most susceptible to blossoming, and tends to bronze when applied full strength. Daniel Smith permanent red deep is less lightfast, with a slightly darker and bluer color. The Schmincke paint was the least lightfast in my tests.

naphthol red lightfastness samples (2004)

after 800+ hours of sunlight exposure: (left to right) Rowney Artists, Schmincke,
Daniel Smith permanent red, Daniel Smith permanent red deep

AVOID. As mentioned above (PR112), the naphthol pigments are available from many pigment manufacturers for many different end uses. This increases the variability in the lightfastness of pigments available to paint manufacturers, which means each paint brand's budget and paint testing practices determine whether their naphthol paints are reliable or not. So it is prudent for the artist to test naphthol paints periodically to ensure that the quality standards do not change over time. I prefer to use something more reliable, such as pyrrole red (PR254) or perylene maroon (PR179). Although both the red and red deep are impressively rich colors by themselves, I don't much like the mixtures they make with most other paints. For nonrepresentational or colorist painting styles, the naphthol reds have more to offer. See also the section on naphthol pigments.

PR176benzimidazolone carmine HF3C (1960)carmine [hue]Daniel Smith094345803027-156,7
PR176+PR101permanent crimsonArt SpectrumW17235901026-127,8

Benzimidazolone carmine PR176 is a lightfast, semitransparent, highly staining, dark valued, intense deep red pigment, currently offered by 4 pigment manufacturers worldwide. Unrated by the ASTM, manufacturer and my lightfastness tests give a rating of "very good" (II) or better. PR176 undergoes a moderately large drying shift, lightening by 10% and losing 23% of its saturation. The average CIECAM J,a,b values for benzimidazolone carmine (PR176) are: 32, 66, 24, with chroma of 70 (estimated hue purity of 61) and a hue angle of 20.

Daniel Smith carmine is the only source of the pure pigment in watercolors; the paint is a lovely color, slightly darker valued than alizarin crimson but very similar in hue, strongly tinting, and inert wet in wet. The paint shows a large total drying shift (substantially losing saturation, and shifting toward blue). The Art Spectrum paint is slightly more intense, more opaque, and less staining, due to the added red iron oxide.

CAUTION. This is an interesting, dark "carmine" color, but its lightfastness is marginal. Interestingly, pigments with a comparable color, such as quinacridone pyrrolidone (PR N/A) or pyrrole rubine (PR264), are not any more permanent. It can be satisfactorily imitated by a mixture of cadmium red deep (PR108) tinted with quinacridone magenta (PR122). It is also one of my recommended substitutes for alizarin crimson. See also the section on benzimidazolone pigments.

lightfastness test sample

unexposed (top); exposed 800+ hours (bottom) — Daniel Smith

PR177anthraquinone red (1913)anthraquinoid redDaniel Smith016445804224-107,7
PR177permanent red deepMaimeriBlu253435602322-96,7
PR177burgundy wine redOld Holland166435502224-113,6

Anthraquinone red PR177 is a marginally lightfast, transparent, staining, dark valued, intense deep red pigment, offered by only 3 registered pigment manufacturers worldwide. The ASTM (1999) rates its lightfastness in watercolors as "fair" (III, "may be satisfactory when used full strength or with extra protection from exposure to light"); my 2004 tests assigned it a variable lightfastness (from lightfast to impermanent) depending on brand. In watercolors, PR177 undergoes a moderately large drying shift, lightening and losing more than 20% saturation. The average CIECAM J,a,b values for anthraquinone red (PR177) are: 33, 76, 24, with chroma of 80 (estimated hue purity of 69) and a hue angle of 18.

One of many crimson lake pigments, it's the paint formerly recommended by Daniel Smith as a lightfast substitute for alizarin crimson. To my eye, PR177 is a little too blue and too saturated, and insufficiently lightfast, for that purpose. MaimeriBlu permanent red deep is the most intense pigment, slightly lighter, less staining and more reactive in water than the Daniel Smith paint, which appears slightly more lightfast. The Old Holland paint is the least lightfast and has a duller color.

CAUTION. An interesting pigment, but easily replaced by other pigments with higher and less variable lightfastness. Either perylene maroon (PR179) or benzimidazolone carmine (PR176) make a better color and mixing match to alizarin crimson, and both are more permanent. See also the section on anthraquinone pigments.

lightfastness test samples

unexposed (left); exposed 800+ hours (right) — Daniel Smith, Maimeri, Old Holland

PR178perylene red (1957)perylene redDaniel Smith029245504328-67,8
PR178scheveningen red mediumOld Holland169125103229-56,7

 Perylene red PR178 is a lightfast, semiopaque, highly staining, dark valued, intense deep red pigment; three manufacturers offer it worldwide. Unrated by the ASTM, my 2004 tests assign it "excellent" (I) lightfastness. In watercolors PR178 undergoes a moderately large drying shift, lightening slightly and losing more than 20% saturation. The average CIECAM J,a,b values for perylene red (PR178) are: 35, 73, 28, with chroma of 79 (estimated hue purity of 67) and a hue angle of 21.

Daniel Smith perylene red is a gorgeous rich red color; strongly staining, it is highly active wet in wet and blossoms readily when rewetted. (I've assigned Old Holland scheveningen red medium here based on colorimetrics and lightfastness: the manufacturer literature labels it PR188, which is apparently incorrect.)

PR178 provides a more lightfast, slightly darker and less saturated alternative to the naphthol reds, though pyrrole red (PR254) is probably a better choice to match the brilliant naphthol color. See also the section on perylene pigments.

lightfastness test sample

unexposed (top); exposed 800+ hours (bottom) — Old Holland

PR179perylene maroon (1957)perylene maroonWinsor & Newton227445903027+18,8
PR179perylene maroonDaniel Smith002346403227-17,8
PR179perylene maroonRowney Artists421445903027+27,8
PR179perylene redRowney Artists529446603022-58,8
PR179perylene maroonDaVinci266paint introduced after my last pigment tests
PR179maroon peryleneM. Graham113paint introduced after my last pigment tests

TOP 40 PIGMENT   Perylene maroon PR179 is a lightfast, transparent, highly staining, very dark valued, moderately intense deep red pigment; five manufacturers offer it worldwide. The average CIECAM J,a,b values for perylene maroon (PR179) are: 29, 60, 21, with chroma of 63 (estimated hue purity of 55) and a hue angle of 20.

The ASTM (1999) and manufacturers rate its lightfastness in watercolors as "excellent" (I); my 2004 tests also make it "excellent" with a very slight loss of color in tints, in some brands, after 800+ hours of outdoor sunlight exposure.

perylene maroon lightfastness samples (2004)

after 800+ hours of sunlight exposure: (left to right) Winsor & Newton, Daniel Smith, Rowney Artists perylene maroon, Rowney Artists perylene red

In watercolors PR179 (like its less permanent sibling, perylene scarlet PR149) undergoes a very large drying shift, lightening by 17% and losing 30% saturation. The four paints tested were receptive to blossoming when rewetted, but varied in how active they were wet in wet.

Daniel Smith perylene maroon is a dark, evocative pigment, slightly darker and much less saturated than the Winsor & Newton, which gives it a distinct brownish cast that is excellent for landscapes, portraits and botanical illustrations. The Winsor & Newton is distinctly a dull, dark middle red, similar to perylene scarlet (PR149), and like perylene scarlet worth exploring for landscape, botanical or portrait work. The Rowney Artists perylene maroon is the same pigment, slightly less concentrated. The Rowney perylene red is a darker version of the same pigment, which shifts the hue noticeably toward violet. (Schmincke also offers a single pigment perylene maroon watercolor in the "red" shade, under the marketing label Horadam aquarell deep red.)

For those who are still using alizarin crimson (PR83), I recommend you try perylene maroon as a replacement. It has a dark, warm, dull color without the bluish overtones common to all red and crimson quinacridone pigments. (Replacing alizarin crimson requires you to rethink the mixtures you used to make with it: the flesh tones, dull greens and dark mixtures possible with alizarin crimson are nicely handled by perylene maroon; the intense orange and violet mixtures you couldn't quite mix with it are much better with a quinacridone rose PV19 or quinacridone magenta PR122.) Its mixing complements include phthalo green BS (PG7), which produces a pure jet black darker than most carbon pigment paints, and perylene maroon stains tenaciously, again like alizarin crimson. See also the section on perylene pigments.

PR188naphthol AS BON arylamide (1911)scarlet lakeWinsor & Newton044334503239-77,7
PR188organic vermilionDaniel Smith042244502138-76,7
PR188permanent redDaVinci265333913236-46,7
PR188+PY65naphthol AS BON arylamide + arylide yellow RNbright red
[discontinued in 2005]
Winsor & Newton042343901042+56,6

 Naphthol AS scarlet PR188 is a lightfast, semitransparent, moderately staining, moderately dark valued, very intense orange red pigment, available from five pigment manufacturers worldwide. The ASTM (1999) rates its lightfastness in watercolors as "very good" (II), although my 2004 tests place it somewhat higher. (In particular, its lightfastness is certainly higher and more consistent than the brands of PR170 I have tested.) Like other naphthol pigments, PR188 undergoes a small drying shift, holding lightness and losing about 15% saturation. It's a beautiful, deep scarlet verging on a light red, the same hue as most cadmium scarlet watercolors (PR188 is an excellent cadmium alternative if price or toxicity is a concern). The average CIECAM J,a,b values for naphthol scarlet (PR188) are: 48, 81, 45, with chroma of 92 (estimated hue purity of 77) and a hue angle of 29.

Winsor & Newton scarlet lake is slightly more saturated, lighter valued, more transparent and more active wet in wet than the other paints tested here. (The term scarlet lake is a traditional label, applied over the past two centuries to several different scarlet pigments or convenience mixtures that are no longer available in commercial paints.) The Daniel Smith brand is also excellent at all dilutions.

CAUTION. This is a lovely scarlet pigment that is more reliable than other naphthol reds. However, there are many saturated scarlet pigments available with better lightfastness, such as pyrazoloquinazolone scarlet (PR251) or pyrrole scarlet (PR255). I like the more lightfast cadmium scarlet (PR108) or pyrrole orange (PO73) for this hue, as I like to use the diluted color as a healthy pink portrait tone, and the naphthol tints are just too prone to fade. See also the section on naphthol pigments.

lightfastness test samples

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

PR209quinacridone red (1958)quinacridone redM. Graham155434303229-117,8
PR209quinacridone redWinsor & Newton230344703131-147,8
PR209tiziano redMaimeriBlu261434102331-137,8
PR209quinacridone coralDaniel Smith092334104231-127,8
PR209quinacridone redUtrecht002324201021-177,8
PR209quinacridone redRowney Artists528334804230-147,7
PR209cherry redHolbein224334803230-177,7
PR209quinacridone redDaVinci2713paint introduced after my last pigment tests

TOP 40 PIGMENT   Quinacridone red PR209 is a lightfast, transparent, staining, moderately dark valued, very intense red pigment; only four manufacturers offer it worldwide. The ASTM (1999) rates its lightfastness in watercolors as "very good" (II); my 2004 tests assigned all brands an "excellent" (I) rating. Like the rose quinacridones, PR209 shows a small drying shift, losing only 12% saturation. The average CIECAM J,a,b values for quinacridone red (PR209) are: 46, 80, 32, with chroma of 86 (estimated hue purity of 74) and a hue angle of 22.

The hue angles reported here are deceiving: although coloristically PR209 is a middle red, equivalent to a cadmium red medium or pyrrole red, those reds are typically darker valued, duller in tints and incapable of mixing a bright purple color with blue paints because they are "spectrum" reds that contain no short wavelength reflectance (view the reflectance curve by clicking on the spectrum icon). In contrast, the touch of "violet" reflectance in PR209 gives it unusual versatility: it slightly mutes the red chroma, making the color less strident than a pyrrole red; the paint shows a bluish cast in undertone, which is very useful for portrait work, and it makes bright, flexible mixtures across both the orange and purple spans of the color wheel, which the pyrroles and cadmiums cannot do.

One of the most popular quinacridones among watercolor paint manufacturers, the paint's hue and saturation are very consistent across brands, though paints do vary in activity wet in wet and readiness to blossom when rewetted. To my eye, the M. Graham quinacridone red has the edge in transparency, saturation, depth of color, and strength of color in tints; it is also somewhat more active wet in wet. Rowney Artists is a very similar formulation. Daniel Smith and Winsor & Newton are slightly lighter valued. Utrecht's paint is distinctively much bluer than other brands, less concentrated but very saturated. — As explained, PR209 is a very useful red. I forgot to mention the lovely coral color of the undertone that harmonizes well with synthetic organic yellows and greens for landscape or botanical work. Creates beautiful mixtures for almost any purpose. See also the section on quinacridone pigments.

PR214disazo condensation red (1951)scheveningen red deepOld Holland024235703330-116,7

Disazo red PR214 is a lightfast, semiopaque, staining, dark valued, intense red pigment; six manufacturers offer it worldwide. Unrated by the ASTM, my own lightfastness tests give it a marginally "very good" (II) rating. The CIECAM J,a,b values for scheveningen red deep (PR214) are: 33, 68, 29, with chroma of 74 (estimated hue purity of 63) and a hue angle of 23.

Old Holland is apparently the only commercial watercolor source. The paint diffuses and blossoms readily, retains its brilliance in tints, but bronzes slightly when applied full strength. — A very interesting pigment in a less frequently used part of the color spectrum. It has the coloristics of a good cadmium red deep, but is more slightly more transparent. Worth investigating. See also the section on disazo condensation pigments.

lightfastness test sample

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

PR216pyranthrone red deep (1901)brown madder [hue]Holbein023425012128+12,5

Pyranthrone red deep PR216 is a fugitive, transparent, moderately staining, semiopaque, dark valued, intense deep red pigment; only one manufacturer offers it worldwide. The ASTM (1999) rates its lightfastness in watercolors as "excellent" (I), though my 2004 tests showed a gross loss of masstone color and complete fading in tints after about 30 days of sunlight exposure (BWS 5) and a total color loss at BWS 6 making it "poor" (IV). The CIECAM J,a,b values for pyranthrone red deep (PR216) are: 39, 68, 30, with chroma of 74 (estimated hue purity of 62) and a hue angle of 23.

Holbein brown madder is the only commercial source; the paint is fairly inert wet in wet and backruns only slightly when rewetted.

AVOID. My tests clearly indicate this is not a reliable pigment. The high rating given by the ASTM may be a typo, a testing error or results based on pigment from a commercial source not currently used by Holbein. Substitutions: The color is close to the far more lightfast benzimida carmine (PR176) or perylene maroon (PR179), both of which are darker valued, more intense and more transparent paints. Either one is a much better choice for a deep red pigment.

lightfastness test sample

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

PR242disazo condensation scarlet (1960)french vermilion [hue]Sennelier675344520440-88,8

Disazo scarlet PR242 is a very lightfast, semitransparent, heavily staining, moderately dark valued, very intense orange red pigment; seven manufacturers offer it worldwide. Unrated by the ASTM, my 2004 lightfastness tests give it an "excellent" (I) rating, though I did find a slight loss in saturation and hue shift toward blue near the end of the test. It may be the most intense red orange pigment available in watercolors, and retains its high chroma without any hue shift in tints; it has a just perceptible, fine granulation when diffused in wet applications. The CIECAM J,a,b values for disazo condensation scarlet (PR242) are: 44, 82, 49, with chroma of 96 (estimated hue purity of 76) and a hue angle of 31.

Sennelier french vermilion is the only commercial source. The paint does not blossom when rewetted, but is very active wet in wet. — A beautiful, intense scarlet pigment, slightly redder and darker than naphthol scarlet (PR188), and apparently very reliable. Like most intense red pigments it has limited mixing potential, and seems worth more as a pure color than as a mixing partner with other paints. See also the section on disazo condensation pigments.

PR251pyrazoloquinazolone scarlet (1960)permanent red
(discontinued in 2002)
Schmincke36123500113608,8

Pyrazoloquinazolone scarlet PR251 is a very lightfast, semiopaque, staining, moderately dark valued, very intense orange red pigment; 3 manufacturers offer it worldwide. Unrated by the ASTM, manufacturer and my own lightfastness tests give it an "excellent" (I) rating. The average CIECAM J,a,b values for pyrazoloquinazolone scarlet (PR251) are: 43, 80, 41, with chroma of 90 (estimated hue purity of 73) and a hue angle of 27.

Schmincke permanent red was the only commercial watercolor source, now replaced by a benzimidazolone/disazo condensation mixture. The paint was resistant to blossoming and inert wet in wet. — This is a very fine scarlet pigment with superior lightfastness and I regret that it has been discontinued. Nevertheless, it is easily replaced by pyrrole scarlet (PR255) or cadmium scarlet (PR108).

PR254diketo-pyrrolo pyrrole red (1983)winsor redWinsor & Newton056244904132-98,8
PR254pyrrol redDaniel Smith005145413432-78,8
PR254permanent red deepRembrandt371144913432-88,8
PR254sandal redMaimeriBlu263234903432-96,7
PR254pyrrol redM. Graham154paint introduced after my last pigment tests
PR254+PO73permanent redRowney Artists371145113438-34,6

TOP 40 PIGMENT   Pyrrole red PR254 is a very lightfast, semiopaque, highly staining, dark valued, very intense red pigment; only three manufacturers offer it worldwide. Unrated (!) by the ASTM, industry and my own tests assign it an "excellent" (I) lightfastness. In watercolors PR254 shows a small drying shift, holding its lightness but losing 15% saturation. The average CIECAM J,a,b values for pyrrole red (PR254) are: 38, 85, 38, with chroma of 94 (estimated hue purity of 78) and a hue angle of 24. Most brands show a strong shift toward blue in the undertone, which creates a rather dull, bruised color in tints and a dulling of diluted color mixtures.

PR254 is becoming increasingly popular with paint manufacturers as the primary replacement for less lightfast middle red pigments, such as the naphthol reds, and the more polluting cadmium pigments. The pigment is very consistent in hue, saturation and texture across manufacturers; it blossoms readily and in most brands is extremely active wet in wet. I like Winsor & Newton winsor red for the depth and clarity of color, and because it is relatively less opaque and is uniquely inert wet in wet. The Daniel Smith pyrrol red is noticeably darker valued, more opaque, and less saturated in tints. The Rowney Artists permanent red lost much of its orange tone after five weeks of sunlight exposure. The Maimeri paint is surprisingly and unacceptably less lightfast. — A widely offered middle red that can is close to a scarlet hue (Schmincke sells it under the label "orange red"). It is a plausible substitute for cadmium red paints in masstone, but lacks cadmium's radiance in tints; it is a good mixing partner with synthetic organic yellows, but these mixtures seem less attractive to me than the equivalent mixture of cadmium red and yellow. Substitutions. A very good color match, with better transparency, can be mixed from quinacridone rose (PV19) and naphthol scarlet (PR188). See also the section on pyrrole pigments.

PR255diketo-pyrrolo pyrrole scarlet (1983)pyrrol scarletDaniel Smith084344704134-28,8
PR255vermilion hue Rowney Artists588344603134-38,8
PR255permanent red mediumRembrandt377145213434-98,8
PR255vermilion [hue] Schmincke365344503136-38,8

 Pyrrole scarlet PR255 is a very lightfast, semitransparent, heavily staining, moderately dark valued, very intense orange red pigment, manufactured solely by Ciba Specialty Chemicals (SZ). The ASTM (1999) rates its lightfastness in watercolors as "excellent" (I), and industry and my own tests agree. In watercolors PR255 shows a small drying shift, holding its lightness but losing about 15% saturation. The average CIECAM J,a,b values for pyrrole scarlet (PR255) are: 44, 81, 41, with chroma of 91 (estimated hue purity of 74) and a hue angle of 27. As you can discover from the hue angle measurements, there is almost no difference in hue between the scarlet and red pyrrole pigments.

The three brands tested here blossomed very readily and were inert wet in wet; the color loses some saturation in tints. This pigment is very consistent across manufacturers; the brands tested here were almost indistinguishable. — This is a lovely middle red pigment, close in hue to many cadmium middle reds. Because it is more lightfast, painters may find it a better choice for a bright red paint than naphthol red AS-D (PR112). See also the section on pyrrole pigments.

PR259ultramarine pinkM. Graham192paint introduced after my last pigment tests

This paint was introduced after my last round of paint color measurements and lightfastness testing, and the pigment has not been tested by the ASTM. The color appearance is a light valued, dull red violet, warmer than ultramarine violet (red shade). The paint would work very well in palettes emphasizing "earth" colors such as raw sienna and venetian red.

PR260isoindoline scarlet (1964)vermilion [hue] extraOld Holland148224804032+58,8

Isoindoline scarlet PR260 is a very lightfast, semiopaque, moderately staining, moderately dark valued, very intense red pigment, manufactured by CPMA (USA). Unrated by the ASTM, my 2004 lightfastness tests give it an "excellent" (I) rating. The CIECAM J,a,b values for isoindoline scarlet (PR260) are: 42, 79, 36, with chroma of 87 (estimated hue purity of 72) and a hue angle of 24.

Old Holland vermilion extra is the only commercial source. The paint is inert wet in wet but blossoms very readily when rewetted. — Another very red scarlet, slightly bluer than pyrrole scarlet (PR255) and at the hue boundary between scarlet and middle red. The paint contains no "blue" reflectance, and so mixes well with other warm colors and with greens. See also the section on isoindolinone pigments.

PR264diketo-pyrrolo pyrrole rubine (1986)pyrrol crimsonDaniel Smith127345803227-96,7
PR264winsor red deepWinsor & Newton725paint introduced after my last pigment tests
PR264permanent alizarin crimsonM. Graham129paint introduced after my last pigment tests
PR264+PV19diketo-pyrrolo pyrrole rubine + quinacridone violetcarmine [hue]Rembrandt318226103322+56,7
PR264+PV19diketo-pyrrolo pyrrole rubine + quinacridone rosepermanent madder purpleRembrandt325334503224+106,7
PR264+PR101diketo-pyrrolo pyrrole rubine + synthetic red iron oxidepermanent madder brownRembrandt324244902229+56,6

Pyrrole rubine PR264 is a lightfast, semitransparent, staining, dark valued, intense deep red pigment, currently manufactured exclusively by Ciba Specialty Chemicals under the name Irgazin Ruby. Unrated by the ASTM, my own lightfastness tests give it a "very good" (II) rating in mixtures with other pigments and as a pure pigment. The average CIECAM J,a,b values for pyrrole carmine (PR264) are: 32, 69, 25, with chroma of 73 (estimated hue purity of 64) and a hue angle of 20.

Daniel Smith pyrrol crimson was the first commercial source for the pure pigment in watercolor paints. (Rembrandt used it earlier, but only in convenience mixtures.) I have not tested Winsor & Newton winsor red deep for lightfastness. The pure pigment hue is identical to benzimidazolone carmine (PR176) or a "red" shade of quinacridone rose (PV19) and is slightly warmer than alizarin crimson, but has a much deeper, richer masstone color when dry. In tints the hue shifts toward violet, closely resembling quinacridone rose. The Rembrandt carmine is close to perylene maroon (PR179) in color and value, the permanent madder purple resembles Winsor & Newton purple madder, now discontinued (see under PR122). All these paints show a moderate drying shift (lose saturation).

CAUTION. An attractive pigment, with a beautiful deep red color. However, as all the tested paints are near the bottom end of acceptable lightfastness, if you use them I recommend you put them through your own lightfastness test. Cadmium red deep or perylene maroon are suitable substitutes. See also the section on pyrrole pigments.

lightfastness test samples

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

PR N/Aquinacridone pyrrolidone (1993)permanent carmineWinsor & Newton226345703225-166,7
PR N/Apermanent alizarin crimsonHolbein209335812223-146,7
PR N/Amadder red [hue] dark
[discontinued in 2007]
Schmincke354335812122-136,7
PR N/A+PR206quinacridone pyrrolidone + quinacridone maroonpermanent alizarin crimson Winsor & Newton225435502121-76,6

 Quinacridone pyrrolidone PR N/A [I just call it quinacridone carmine] is a lightfast, transparent, staining, dark valued, intense deep red pigment, offered by only one pigment manufacturer worldwide (Ciba-Geigy). Unrated by the ASTM, manufacturer and my own 2004 tests assign it "very good" (II) lightfastness, with a tendency to lose lightness in tints after about 500+ hours of direct sunlight exposure (roughly halfway between BWS 6 and 7), and to lose chroma in masstone only in BWS 7. In watercolors, this pigment undergoes a small drying shift, holding its lightness but losing about 15% saturation. The average CIECAM J,a,b values for quinacridone carmine (PRN/A) are: 33, 74, 26, with chroma of 79 (estimated hue purity of 68) and a hue angle of 19.

It is not assigned a color index name, according to the Society of Dyers and Colorists, because it is a proprietary, crystallized compound of two separate pigments (based on the dark color, my guess is these are a dark shade of quinacridone PV42 and the diketo-pyrrolo pyrrole PR254). With an average CIELAB hue angle of about 24, this pigment is very close to the psychological unique red (along with alizarin crimson PR83, pyrrole rubine PR264 and anthraquinone red PR177), as explained in the color vision section on the four unique hues. (It's an excellent choice for color point 4 of the color wheel, but some artists may prefer a slightly warmer hue closer to quinacridone red, PR209, at hue angle 30.)

This pigment is very consistent across the three paint manufacturers that offer it because it comes from a single pigment manufacturing source. Winsor & Newton permanent carmine and Schmincke red madder dark are the pure pigment; the Winsor & Newton permanent alizarin crimson is a convenience mixture with quinacridone maroon, although you can see from the hue angle and value range for each paint that the permanent carmine, not the permanent alizarin crimson, is actually a closer color match to Winsor & Newton's alizarin crimson (hue angle 26, value range 59). The Schmincke paint is slightly darker but just as saturated in masstone, handles very nicely, yet seems slightly grayer in tints.

CAUTION. This is a very useful pigment in place of cadmium red or quinacridone red, especially for portraits and botanical paintings. It mixes superb neutrals (near black and silvery grays) with phthalocyanine green BS (PG7). However its lightfastness is at the lower end of the acceptable range, and for really reliable tints you may want to substitute in its place the paint pair of perylene maroon (PR179) for near black or dull warm mixtures, and quinacridone magenta (PR122) for intense red and orange mixtures. If you do use this pigment and want a close match to natural alizarin, mix PR179 with a touch of pyrrole orange (PO73) to simulate the fiery purpurin undertone. See also the section on quinacridone pigments.

lightfastness test samples

unexposed (top); exposed 800+ hours (bottom) — Holbein, Winsor & Newton

red paints made with pigments in a different color index category

PV29perylene violet (1936)perylene violetWinsor & Newton470337012330-21.,.

Perylene violet PV29 is a lightfast, semitransparent, heavily staining, dark valued, dull deep red pigment. (The masstone color measures as scarlet, but in tints the hue shifts strongly toward red violet.) Unrated by the ASTM and by me, the performance of other deep red perylenes suggests this pigment has "very good" (II) lightfastness. — Winsor & Newton perylene violet is currently the only source of this pigment in watercolors. The masstone color is a very dark and intense scarlet, which shifts toward a dull red violet in tints. The paint makes an interesting shadow accent color for portraits and figures, but used lightly: it has a purplish brown color when dried that looks dull in heavy concentrations. It has a significant drying shift, losing lightness and chroma by about 30%. For most painting situations I would prefer the more versatile perylene maroon (PR179). Both paints mix very dark, warm near neutrals with perylene black (PBk31). See also the section on perylene 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.