4. Single-Pigment Paint, Part Four: Identifying Ingredients

Old Holland’s colors presented by Jackson’s Art Supply, UK

I like to keep things simple, and tube colors are no exception. Reducing your palette to its essentials brightens and tightens your paintings. 

In this series I’m going to explain:

Part 1. Who are the best manufacturers of artist-grade extra-fine oil colors
Part 2.
What single-pigment colors are essential for your paint palette
Part 3.
Where to buy single-pigment paint
Part 4.
How to tell what pigments your paints use
Part 5.
Why you should limit your palette to single-pigment paints


Part 4

How do I tell what pigments my paints use?

There are several resources at Old Holland, Charvin and M. Graham. I have bundled them here, with further commentary. There are also several extremely dedicated, online third-party resources regarding pigments (and a whole lot more) to which my simple articles owe a great deal:

Handprint - a polymathic website by one Bruce MacEvoy from Sonoma, California, which among Shakespeare’s sonnets, genetics, and astrophysics, there happens to be wedged a massive collection of personally investigated color, color theory, and watercolor science.

CAMEO - the Boston Museum of Fine Arts’ wiki on art materials found in their collection and applicable to many disciplines.

ArtisCreation - one wildly and widely encompassing Pigment Database.

The pigments in my preferred paints are all listed on the tubes and charts from the manufacturers. For what it’s worth, Graham’s chart is ideal. Other manufacturers often omit pigment info from their labels and/or do not produce charts. The one heading this part is actually produced by an art supplier, Jackson’s, based in the UK with an outpost in the US. I’ve never used their service, so I have no recommendation, but I sure do like their chart for Old Holland; in fact, it’s better than Old Holland’s. Let’s use it as an example.

 

Jackson’s Old Holland Burnt Sienna oil paint key broken down by components


In the first, top part of the key, you see the paint color’s value sample with its Old Holland number and name.

The second, bottom part of the key is Jackson’s coding: Old Holland’s price point (1), meaning lowest; the Colour Index code; its lightfastness; and its opacity.

The third panel highlights the Colour Index code - PBr for Pigment Brown - and 7, for which brown it is. We’ll come back to this code in a moment.

Then in the last panel there are the bold sun shape - indicating Burnt Sienna being the most lightfast, and also the solid circle - meaning it’s fully opaque in solution with the oil vehicle.

What you’re looking for first on any tube or chart regarding single pigments is this group of letters with a number from the third panel. For example, you might see PW1 or PY35 or PB27 instead of PBr7.  Each of these is a single pigment, and is standardized on the international Colour Index. Any tube that includes a string of Colour Index designations (such as Old Holland’s Naples Yellow Reddish Extra - already a suspect title - which includes PW4, PW6, PY53, and PO34: two whites, a yellow, and an orange, all of which clash with each other chromatically) will force you to use it essentially by itself as a convenience blend rather than as a single-pigment paint in a functional palette for risk of muddying it when mixing.

There is sometimes another designation on the charts, the Colour Index Number, such as 77947 which is synonymous with PW4, but they are almost never on tubes, so you needn’t worry about it. 

Let’s see how Graham’s is similar:

Graham’s color chart breakdown key

Pigment

Graham’s Burnt Sienna is listed as PBr7, but with an asterisk. They are noting that the pigment has been calcinated - or baked with oxygen - to achieve this hue.

Raw Sienna is also PBr7 on Graham’s chart; that makes sense, right? Burnt Sienna is just toasted Raw Sienna. Sounds logical… Then why are their Burnt and Raw Umber paints also PBr7? Hmm… a mystery. (More on why two different paints use the exact same pigment below).

Lightfastness

Their Siennas show a lightfastness is rated LF 1, for a permanent rating. While it seems each manufacturer uses the four-stepped lightfastness ladder in their own way, colorists generally agree on the four steps but continue to differ as to how they present them making it confusing for the artist.

Opacity

Graham’s opacity/transparency scale indicates their Burnt Sienna is ST or semi-transparent, rather than Old Holland’s opaque rating. This could be because of different sizes of the grind of the pigment powder, and as as a result of their different vehicles: walnut vs. linseed oils.

Drying

And finally, Graham includes on their chart a drying speed, with F meaning fast.

Note: as pigments are made of different molecules, each of these molecules oxidizes - or dries - at different rates depending on their own structure, the properties of the vehicle in which they are suspended - walnut oil in this case - and the environment in which the painting is applied and then cured.

So how are Graham’s Siennas and Umbers the same pigment? Well, hold on a sec… curveball:

Yes, that’s right… Charvin’s Siennas and Umbers are blends.


Fundamentally, PBr7 is known as Iron Oxide in the paint-making world. It is often qualified by Brown/Natural/Red/Synthetic. Iron Oxide is just rust from dirt. In these cases, rust from dirt found around Siena and Umbria, Italy. Iron Oxide is the one of the oldest pigments in use, going back to the earliest civilizations and cave paintings. Even though chemically it has the same composition of molecules, each pigment contains variables: impurities such as additional minerals; size; and how it was grown. An apple is an apple until you realize there are different species, strains, and hybrids. Sienna and Umber are both Iron Oxide, but they’re like the difference between a Fuji and a Grannysmith.

Charvin has decided, however, they know better than Mother Nature and have crafted some color recipes they think are Sienna-ier and Umber-ier than what actually comes out of the ground in its original form. Remember my comments about PBk being difficult? Charvin has added some to all of their blends. Why, Charvin? Why?

Now you might be beginning to see why having a guide for which paints to buy from whom isn’t such a bad idea after all… Just download it here already.

One more thing: Temperature

Embedded within my super-savvy list of essential colors, I correlate each paint’s name with its pigment and add its color family as well as temperature to assist you with buying and then mixing.

Temperature is something few artists and educators discuss enough. I don’t mean color-wheel warm vs. cool, but internal color temperature. It’s esoteric and tons of fun. Handprint presents some nerdy investigations into the why and how neutrals are made considering ancillary properties of color… including internal temperatures. Neat!

So… now you have just enough information to be dangerous. Think you’re ready for a little more? Read on to learn why you really should limit your palette to just single-pigment paints and how to apply the info you’ve absorbed in Parts 1 - 4.


Questions? Comments? Shoot me a message below.


Next up: Part 5. Why they just work >>