What’s in Your Paint?

Knowing the contents of a paint can help you with a number of things:

• Make better decisions when buying new paint
• Figure out what paints you already have and avoid duplicating them with a paint that has a different name, but uses the same pigment
• Understand if a paint is single-pigment or a convenience mix, and how you can mix it yourself
• Determine if a paint is not really what the name of it says
• Discover/Recognize the characteristics of the paint

The names of artists’ paints are historical, eponymous, whimsical, chemical, and geographical – but mainly named to sell paint (The modern trend is to use chemically-derived names – to reflect the ‘scientific’ approach to paint.)

The Society of Dyers and Colorists (SDC) assigns a Color Index (CI) to each new pigment that comes on the market.  The American Society for Testing Materials (ASTM) sets the standards of what must be on the label of a tube of paint, and one of those requirements is the CI code for the pigment(s) used in the paint.  In order to get ASTM’s stamp of approval, each tube of must tell us exactly which pigment(s) it contains.

The CI (Color Index) is the true indication of what pigment you’re getting when you buy a tube of paint.

• Paint names and descriptions are often misleading – usually for a reason – to sell more paint to artists by using alluring names or by describing them in a romantic way. Many names of paints that no longer exist are still used. The CI is the only way to find out the actual pigment
• Most paints are single-pigment paints. That is they only contain one pigment – they will only have one CI.
• Some paints are mixes, often termed Convenience Mixtures. These will contain two or more CIs
• ‘Hues’, ‘New’, ‘Permanent’. If you see a term like this in the paint’s name, beware that its not the real McCoy. The manufacturers are constantly coming up with new modifying words to avoid having to admit the paint does not actually contain that pigment, and often they don’t add these modifiers unless they are called out by the ASTM. An example of this is ‘Cadmium Red Hue’.  Cadmiums are expensive pigments, so many manufacturers will substitute other, less expensive, pigments.  They are not supposed to call it ‘cadmium’, so they get by this restriction by calling ‘ Cadmium Hue’.

Pick up one of your tubes of paint and look at the label. Somewhere, you should see the CI.  It can be identified as a short code starting with the letter ‘P’

• The ‘P’ stands for ‘pigment’. Occasionally you might run across an ‘N’ instead.  This means a ‘natural’ and most often means it is made from something organic and has very poor light fastness.
• Right after the ‘P’ you will see a color initial (Yellow, Orange, Red, Blue, Violet, Green, Brown, Black, or White),
• this will be followed by a number assigned by the SDC. (1-3 digits)
• Example: PG 7 – commonly referred to as Phthalo Green, Blue Shade. 

An excerpt from  the Dick Blick site detailing ‘Davy’s Gray’ by W/N

The Pigment Information Tab 

Author: John D McLaren
May 5, 2022