We experimented with creating simple oil based paints with the various organic red pigments. Using a mortar and pestle, each pigment (cochineal, lac, madder root and brazil wood) was ground as finely as possible. We chemically altered some of them with the addition of either alum or cream of tartar. We gradually added the powders to a small amount of linseed oil to create a paste-like consistency and then applied the paint to watercolor paper with a damp paintbrush. It is important to note that the paints created were experimental with no controls or consistent measurements.
Cochineal and Lac Paints
The most successful paints were the cochineal based paints. We created four different cochineal based paints: pure cochineal, cochineal + alum, cochineal + cream of tartar, cochineal + cream of tartar + alum.
When the cochineal paint dried it was semi-transparent and had a pink hue. It resembles the color of the dried cotton from the cochineal dye bath.
The cochineal and alum paint is the most successful in terms of both hue and transparency. It is less transparent and more intense than the pure cochineal paint.
The least successful paint was the cochineal and cream of tartar. When first applied to the watercolor paper it appears to be a typical red but almost immediately fades to brown. Once dry, it is an inconsistent brown with a hint of pink.
The combination of cochineal, alum, and cream of tartar had the strengths of the alum and weakness of the cream of tartar combinations. It did not fade as much when first applied to the paper. The translucency is similar to that of the pure cochineal and the color is just slightly more brown.
The lac paint was not as successful as the various cochineal paints. When applied to paper the color is very similar to a brick red, however, it did fade. The paint also has a more grainy consistency than the cochineal despite the fact that it can be ground to into a fine powder.
Madder Root and Brazil Wood Paints
The plant based paints were not successful. This was largely due to the fact that they did not adhere well to the linseed oil. They are also more difficult to grind as finely as the insect based pigments and thus the particles are too large.
When combined with cochineal, the madder root adhered well enough with the linseed oil to use it as a paint. Once dries the color is a dark brown. Both the pure madder root and pure brazil wood did not adhere well enough with the oil and both created a translucent and grainy brown.
Pictured on the right: Ground madder root mixed with linseed oil did not form a paste.