MADDER LAKE AND HARRISON RED
BOTH of these colors are aniline colors and therefore artificial. There is some Madder Lake on the market which is made from the Madder Root but it does not differ from the artificial in the slightest degree and both the natural and the artificial are absolutely permanent under normal conditions. The artificial is sometimes sold under the name alizarine.
Madder Lake is transparent when used as a glaze and it can be mixed with a number of pigments with which it does not interact, but it must not be mixed with the iron pigments that contain water, and these are principally all the Ochres and Siennas, but as a glaze it may go over any color without being decomposed. It has a record for permanency of several hundred years and is at least of essential importance in portrait painting.
Harrison Red is rather a complex aniline color, exceedingly brilliant, but it has some defects which the painter should know. In the first place it bleeds very slightly, that is to say, if Zinc White or Flake White is painted over pure Harrison Red, the Zinc or Flake will turn a pinkish brown, which is due to the fact that the linseed oil, or other drying oil will absorb part of the dye out of Harrison Red. The painter, therefore, in using Harrison Red must be careful of this defect. Harrison Red must not be mixed with an iron color like Ochre, Sienna, or Raw Umber, otherwise its brilliancy is slightly marred. It is similar in many respects to Deep Vermilion, excepting that it is many times stronger than Vermilion. It can be reduced with Permanent White (Blanc Fixe) without materially lessening its brilliancy.