PIGMENTS.
Names of pigments are not always synonymous with the colors. Dutch pink is yellow, verditer is blue, lake is not purple-blue always, but sometimes green, yellow, brown, etc., or it may be found as a pigment color, with a chalk base, or body.
Before proceeding to describe the actual method of mixing, a few general remarks on colors may be given. White lead is used for the base of paints, because that pigment possesses greater covering properties, or body, as it is technically termed, than any other. Zinc white may be used for a base under certain conditions, and color mixed with it will not be so likely to fade as when mixed with lead. The tendency of zinc white, however, to chip and crack renders the addition of lead necessary in some cases. When practicable, the natural earth pigment should be used for tinting purposes in preference to those which are manufactured. Raw umbers, raw siennas, etc., will be found to last longer than burnt umbers and burnt siennas. As a rule, burnt umber should not be used for outside painting, but the required shade should be obtained by mixing lamp black and an oxide color, such as Venetian red.
Common colors include lamp black, red lead, white lead, Venetian red, umbers, and all other common ochres, such as greys, buffs, stones, etc. Superior or ornamental colors include bright yellows, warm tints, blues, mineral greens, etc.
In compounding pigments for painting, there is yet a further matter requiring some little consideration by the painter. All blue pigments are not chemically suitable for mixture with yellows or reds, nor all yellows with reds; in fact, a knowledge of the chemical source and affinities of pigments is almost a necessity to the painter and decorator.
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