POWDER COLOURS are the purest: they may be mixed with gum arabic and water. Yolk of egg and water is sometimes used as a medium (or white of egg) (see pp. [166], [179]). It is more convenient for the beginner to use prepared colours, which are ready and dependable.
CAKE COLOURS rank next to powder colours for purity: they seem to need tempering with a little gum or honey or glycerine (or egg—see above) for use on ordinary parchment.[34] Used [p176] plain with water, they are apt to flake off when dry.
PAN COLOURS are very safe for ordinary use.
TUBE COLOURS sometimes seem to have too much glycerine; they are, however, very convenient for preparing mixed colours in any quantity, because of their semi-fluid condition, and because the amount of each colour in the mixture may be judged with considerable accuracy by the length which is squeezed out of the tube (p. [178]).
COLOURS FOR PENWORK, &c.—For simple letters or decoration it is well to use a pure
- RED—neither crimson nor orange tinged:
- BLUE—neither greenish nor purplish:
- GREEN—neither bluish nor “mossy.”
A little “body colour” is generally used with blues and greens to keep them “flat” (p. [118]). These colours should be mixed as required, and be diluted to the right consistency with water (see p. [118]). Colour which has been mixed and in use for some time—especially if it has been allowed to dry—is best thrown away (see mixing size, p. [148]).
If there is much rubricating to be done, a quantity of each colour sufficient to last several days may be mixed, and kept in a covered pot. A little pomatum pot is convenient—the smaller the better, as it keeps the colour together, and does not allow it to dry so quickly.