The main coloring agents in the roots of the madder plant are alizarin, purpurin, and pseudo purpurin. All of them are derivatives of anthraquinone.The colorants are bound to inorganic substrates such as aluminum hydroxide or calcium carbonate.The chemical stability of all colorants contained in madder lake is not very high and it cannot be used in fresco. Red lakes containing alizarin and pseudo purpurin show very good lightfastness, whereas lakes containing purpurin are much less stable. As purpurine is contained in madder, these lakes are not stable to light. There are no known incompatibilities with other pigments. Mixing madder lake with lead white prevents its cracking.
RubiaCochineal: Natural red 9 (NR 9)C.I. 75330; 75420From Old English mædere and Old Norse maðra, from Proto-Indo-European modhro– “dye plant” (source also of Old High German matara “madder,” Polish modry, Czech modry “blue”). From Online Etymology Dictionary
Preparation of the natural pigment from madder roots according to a 19th-century recipeBoil 1 part of madder in from 12 to 15 pints of water, and continue the ebullition till it be reduced to about 2 lbs. Then strain the decoction through a piece of strong linen cloth, which must be well squeezed; and add to the decoction 4 oz. of alum. The tint will be a beautiful bright red, which the matter will retain if it be mixed with proper clay. In this case, expose the thick liquor which is thus produced on a linen filter, and subject it to one washing, to remove the alum. The lake, when taken from the driers, will retain this bright primitive color given by the alum.
Madder has been used since antiquity for dyeing textile materials and in paintings as well. The following graph gives the frequency of its use from the 14th till the 19th century in the paintings of the Schack Collection in the Bavarian State Art Collections in Munich (1).Examples of use
I disagree with those who assert that Titian and El Greco painted on a tempera underpainting. ...In contrast to Titian, El Greco very frequently employed glazings ...In El Greco we find a curious combination of tempera school ideas associated with a freedom of the brush stroke surpassing that of his master, Titian. Like the tempera painters, El Greco often underpainted in grisaille and glazed upon such a monotone underpainting the fiery hues of madder lake, verdigris, azurite blue and yellow (probably Indian yellow). This... largely accounts for the brilliance and extraordinary luminosity... But El Greco's grisaille... was brushed on roughly and the texture of the superimposed color often does not correspond with that of the grisaille. This... is an entirely unorthodox method. Entirely unconventional also was his use of the madder, which, at times, he applied with an extreme impasto defying the nature of this glazing color. Frederic Taubes, Studio Secrets (1943) pp. 10-11.
Source: El Greco