Monday Morning Art School: how to read a paint tube

Modern painters expect to open a new tube of paint and squeeze out something recognizable. A tube of ultramarine blue made by any reputable manufacturer will have approximately the same amount of oil, and dry in about the same time to about the same gloss and transparency. The differences in binder and pigment load are subtle compared to the products available before the twentieth century.

That’s not by accident. Paint manufacturers subscribe to voluntary associations of quality control. One of these is Colour Index International (CII), a database dating back to 1925. It contains over 27,000 individual products sold under 13,000 different product names. This standard classification system ignores historic, proprietary, and generic names and gives you ‘just the facts, ma’am.’

Just as Benjamin Moore uses names like “Yukon Sky” to peddle grey paint, art paints are often marketed with evocative names. These names appeal to our sense of tradition, even when the old paint has no relationship to its namesake. For example, Indian Yellow no longer has anything to do with the urine of cattle which were fed mango leaves. Today it is made from lightfast diarylide yellow (PY83). If you buy Naples Yellow thinking you’re buying an historic pigment, think again: the modern paint is a convenience mix replacing the historic lead antimonate, which would do you and your painting no good.

Expect to find, at minimum, the following information on the label of your paint tube:

The CII code consists of two letters and some numbers. Most paints start with a “P” which means it’s a pigment, not a dye. The next letter is the color family:  PR is red, PY is yellow, etc. The number is the specific pigment included in the tube.

Save this link somewhere accessible from your phone: https://www.handprint.com/HP/WCL/waterfs.html

You’ll need it when you shop. This is Bruce MacEvoy’s Handprint pigment guide. It was built for watercolors but is generally true across all media. (Watercolor is the canary in the coalmine of pigments). All painters should understand lightfastness, transparency, and color shift. Granulation, bloom and diffusion, however, are watercolor-specific issues. 

Handprint doesn’t rate pigments for toxicity but comments on it in the notes. Most modern pigments are safe for the painters. For the manufacturers (who may be children in a third-world country) it’s another story.

When you find two colors from different manufacturers that look the same, check their CIIs. Chances are that they contain radically different pigments.

A “hue,” is made of a blend of less-expensive pigments. There is nothing inherently wrong with these pigments, but they don’t behave the same as the more expensive ones, and you should at least know what you’re buying.

Generally speaking, there’s little to be gained by buying a hue mimicking a more expensive pigment. If you are comfortable painting with a hue, then learn what’s in it and mix it yourself. You always have the greatest flexibility by working with pure pigments (rather than mixes) out of the tube.

Most manufacturers include their own lightfastness ratings on the tube. This is a measure of how fast the color fades. If it’s not listed, look it up.

The series number tells you the price. Why are some paints more expensive than others? That’s based on the raw pigments and what they cost the maker. Are pricier pigments better? Not by a long shot. Twentieth-century manufacturing gave us a new world of inexpensive pigments, which tend to be less toxic, higher in chroma and lightfast.