Coupled with my Art History classes, I learned a great deal about pigments and their evolution. Naturally, we are not talking about natural evolution, but the way technology and science have helped us along as artists.
Since I began discussing my love of historical pigments and the process of working with them, I have noticed more conversation in circles of artists about making paint from pigments and also about the pigments we use. There is a lot of confusion out there, so I thought I’d cover some basics. To begin, I thought I’d highlight the three most valuable reasons to deepen your understanding of pigments.
- Safety– Historically the bright natural paints have been deadly to handle incorrectly. Restoration painters must use them diligently to protect themselves from being poisoned. Modern synthetic pigments can give you safer alternatives to Lead White for example.
- Longevity– I can make a brilliant blue from the flower petal of a common garden plant, it is beautiful, bright, and safe. However, it has a short life when exposed to UV light. Other pigments have the possibility of interacting with chemicals in the air, which can cause their color to change over the course of time.
- Transparency– Transparency is very valuable no matter your medium but is especially important in watercolor. Natural Verdigris lacks the brilliance and transparency of Sap Green, but as a mineral, it does not fade. Whereas historical Sap Green will fade. If you are using the modern synthetic version, you get the best of both worlds.
Pigments can be first divided into Natural or Synthetic. Natural pigments can be found or made through items accessible in the natural world and processed for use without modern chemistry or technology. Synthetic pigments are often dependent upon modern technology and chemistry as part of their production. In the end, pigments fall into one of the main categories below. They are linked to an external website, Handprint.com by Bruce MacEvoy , MacEvoy,a solid source for understanding the categories better.
- Natural Organic: Such as Indigo Blue or Weld Yellow.
- Natural Inorganic: Such as Orpiment or Cinnabar
- Synthetic Organic: Such as the Quinacridone family
- Synthetic Inorganic: Such as Titanium Dioxide
After deeming a pigment natural or synthetic a pigments can be labeled Organic or Inorganic, and one must remember that some are compounds of both. Let’s look at Ultramarine Blue, it is one of the trickier pigments to classify.
Historical Ultramarine Blue which means blue beyond the sea, was a natural and inorganic pigment derived from lapis lazuli. It was and is a very expensive pigment but it is remarkably beautiful.
Contemporary Ultramarine Blue is a Synthetic pigment which is usually a compound of both organic and inorganic materials. Notably Kaolin Clay, charcoal, sulfur, anhydrous sodium sulfate, and anhydrous sodium carbonate.
Modern Quinacridone pigments, my favorite being Quinacridone Gold, are synthetic but composed of organic compounds.
My favorite natural yellow of all time is Orpiment which is the mineral arsenic sulfide. It is like many bright natural pigments, very very dangerous to work with. It is not my favorite because it is dangerous, but because it is so beautiful and is the bright lovely gold pigment used in the infamous Book of Kells.