the color ingredients in paint
Artist’s paint containers have useful information about the make-up of the paint color. Understanding this data has practical benefits to artists, but there are also some limitations to be aware of.
Two key pieces of information found on the tube are the pigments used to produce the specific color as well as how opaque or transparent the color is. Some paints also tell what vehicle is used to carry the pigments, such as linseed, walnut, or safflower oil.
Reading a paint tube
1) Opacity information
Identifies whether the color is opaque, semi-transparent, or transparent. Some companies identify this with symbols- a black square being opaque, a half black/half white square being semi-transparent and a white square being transparent
2) Lightfastness Rating
How the color saturation holds up over time with exposure to light. Usually rated by a Roman numeral, with one being the best rating and five being the worst.
3) Pigment Information
Identifies the specific pigments used in the paint using a system of letters and numbers.
4) Vehicle/Binder Information
Identifies the specific oil used to carry the pigment. The most commonly used oils are linseed, walnut, and safflower.
The image shows paint from four different companies. They all contain pigment, lightfastness, opacity and binder information but display it in different ways.
They all use the same letter and number system to identify pigments.
For example, Williamsburg and Windsor & Newton choose to use symbols to convey opacity information.
The system to identify the pigments used in a color is a series of letters followed by numbers. Some of the pigments in the tubes picture here are PB15:3, PO20, PR177, PR83 and PBr24. The letter ‘P’ stands for pigment and remaining letters define the specific color. PB would read as ‘pigment blue’. PO would be ‘pigment orange’ and PBr would be ‘pigment brown’. The numbers following the letters identify the exact pigment within that specified color family.
In some cases the pigment code contains numbers separated by a colon, such as PB15:3 as seen on the tube of M Graham Phthalo Blue above. Gamblin uses PB15:2 in their formulation of Phthalo Blue. Variants such as these have slightly different hues. In the case of Phthalo blue, PB15:2 is warmer while PB15:3 is cooler and often referred to as Pthalo Blue Green Shade.
Why does it matter? How it can benefit you
When selecting paints of different brands with the same name always check the pigments used in the color.
In the example shown here, Winsor & Newton’s Burnt Sienna and Gamblin’s Burnt Sienna are composed of different pigments.
Gamblin’s Transparent Earth Red would be a better match because it contains the same pigment as Winsor & Newton’s Burnt Sienna.
We typically use Gamblin paints in our studio. A while back we ran out of Gamblin’s Green Gold and needed more quickly. The only art supply store in town only carries the M Graham brand. A online cross-reference of the pigment in Gamblin’s Green Gold, PY129, revealed that Azo Green was made using the same pigment.
Knowing the pigment make-up saved the day!
Many colors contain a combination of pigments, which are listed on the tube. Knowing this ‘recipe’ can allow you to re-create close versions of these colors if you have the individual pigments that make up the ingredient list on a specific color. There are a few examples in the following image.
Checking the pigment ingredients on colors will reveal that different companies have different ‘recipes’ for certain colors that share the same name. For example, Gamblin makes their Payne’s Grey with PB29 and Pbr7, which is a blue and a brown. Williamsburg makes their Payne’s Gray with PB29 and PBk9. Both companies use PB29, which is ultramarine blue but one uses a brown and the other a black as the second pigment. This will give these two colors a slightly different appearance even though they have the same name. Not all colors are created equal, and you may prefer one brand’s version over another if they use different pigments.
Limitations- Pigment codes don’t tell the whole story
Individual pigments can be treated with heat to produce a range of colors, in the same way that toasting bread can change the color of the bread depending on how long it is toasted.
There is generally no indication on the label identifying these variations in certain pigments. Gamblin’s Raw Sienna, Burnt Sienna, Burnt Umber and Raw Umber show only PBr7 as the pigment used. Gamblin’s Cobalt Blue and Cobalt Teal show only PB28 as the pigment used, but all these colors are quite different in appearance.
This is important to keep in mind when trying to reproduce certain color ‘recipes’ using the ingredients listed on a tube. For example, Gamblin’s Payne’s Grey lists PB29 and PBr7 as the pigments in the paint. There is no indication which PBr7 is used, and mixing Raw Sienna (PBr7) with Ultramarine Blue (PB29) will produce a different result than mixing Raw Umber (PBr7) with Ultramarine Blue (PB29).
Knowing the meaning behind the information on paint tubes comes with a number of practical applications. The information presented here can also be wide ranging in its application since most artist-grade paints (oils, acrylics, watercolors, gouache, etc) provide pigment data.
Let us know in the comments if you have any questions or if you’ve found other practical benefits to knowing pigment information.