Of Pigments

Remember colors? This question sounds silly because we really don’t perform any conscious process of recollecting specifics about colors (most of the time!). Every object we see, the information we gather visually, our memories, imaginations and even our dreams have colors. This post could very easily begin to move in several different directions at this point. Like for instance if we mention “dreams” then we could bring in Sigmund Freud! But here when we say “colors”, (which is what we are going to say :), we are going to talk about ‘Pigments’.

Now when we begin talking about pigments, we still have multiple things that we can discuss: physical basis, chemical understanding, technical understanding, historical (history of pigments, not history of art), artistic etc. Even from an ‘artistic’ point of view, there are multiple aspects which will very soon convert this post into a good fat datasheet. (No, this is not going to happen!)

So here I am going to limit the scope for this post to an overview about pigments to make things easier.

What is a pigment: A pigment is a dry coloring matter, usually an insoluble powder. When these dry colorants are mixed with binders also called ‘vehicles’ (such as linseed oil, resins, acrylic, wax etc.) we get various types of paints. But besides pigments and binders, paints can also contain various adhesives, stabilizers, preservatives and antioxidants (dryers) etc.

This means watercolors, pastels, gouache, color pencils, acrylic paints or oil paints, they usually share same pigments but different binders.

Pigment Categories: Pigments have three basic categories

1. Organic substances (made from natural sources. Color example: Rose Madder)
2. Inorganic (made from sources like minerals and metals. Color example: Burnt Sienna)
3. Synthetic pigments (artificially manufactured. Color Example: Cobalt Blue)

Pigment Types: Artistically, there are 3 broadly defined pigment types (Source: .winsornewton.com)

1. Earth colors - ochres, siennas, umbers, Mars colors
2. Traditional colors - cobalts, cadmiums, titanium, ultramarines
3. Modern colors - phthalocyanines, quinacridones, perylenes, pyrrols

Organic pigments made from natural sources have been used for centuries, but most pigments used today are either inorganic or ‘synthetic organic’ (containing carbon atom structure same as original organic pigment) ones. Industrial and chemical revolution in the 19^th century changed the scenario rapidly and today what we get as consumer colors are mostly made out of synthetic pigments. Historically and culturally, many famous natural pigments have been replaced with synthetic pigments, while retaining their historic names. It is indeed good to know about colors more than just their names!

And how about some trivia on the way out?

1. More than 15,000 years ago cavemen began to use color to decorate cave walls. These were earth pigments, yellow earth (Ochre), red earth and white chalk. In addition they used carbon (Lamp) black by collecting the soot from burning animal fats.
2. Ancient Romans used to import ‘indigo’ as a pigment from India by Arab merchants. They used it for medicinal and cosmetic purposes. It was an expensive luxury item!
3. ‘Indian Yellow’ was once produced by collecting the urine of cattle that had been fed only mango leaves. Modern hues of Indian Yellow are made from synthetic pigments. (Relax!)
4. Vermilion was developed in China around 2,000 years before Romans started using it. Vermilion was made by heating mercury and sulphur.
5. Ultramarine was originally produced from the semi-precious stone lapis lazuli. In the 1820's a national prize of 6,000 francs was offered in France to anyone who could discover a method of artificially making ultramarine at a cost of less than 300 francs per kilo. J B Guimet succeeded in 1828. Known as French Ultramarine ever since, the pigment is chemically identical to genuine ultramarine.
6. Lac is a red colorant originally made in India, which gave rise to the term "Lake", meaning any transparent dye-based color precipitated on an inert pigment base, used for glazing. During the High Renaissance in Italy, Lac was the third most expensive pigment (after gold and Ultramarine), but most artists thought it worth the expense.
7. In 14^th century, the Italians developed the range of earth pigments by roasting clays from places called Sienna and Umbria to make the deep rich red of Burnt Sienna and the rich brown of Burnt Umber.
8. The oil paint pigment ‘van Dyck brown’ is named after 17^th century’s great Flemish painter Anthony van Dyck.
9. Emerald Green was a very popular wallpaper color but unfortunately in damp conditions arsenical fumes were released from it. It is thought that Napoleon died as a result of arsenic poisoning from the wallpaper in his prison home on the island St. Helena.
10. ‘Payne’s gray’ is named after the 18th century watercolorist William Payne, this dark blue-grey colorant combines ultramarine and black, or Ultramarine and Sienna. It was used by artists as a pigment, and also as a mixer instead of black.

Update: This article has also been incorporated in the content resource of the ‘NonToxicPrint.com’ by Friedhard Kiekeben. ‘Non toxic print’ is one of the best places on the internet to learn about various non-toxic printmaking techniques and safe painting practices for artists.