XVII.—Silk Green.—Silk green, 10 parts, by weight; chrome yellow, pale, 1/2 part, by weight; lead sulphate, 5 parts, by weight; varnish, 30 parts, by weight; benzine, 1/2 part, by weight.
XVIII.—Brown.—English red, 10 parts, by weight; ocher, light, 3 parts, by weight; varnish, 30 parts, by weight; benzine, 1/2 part, by weight.
XIX.—Ocher.—French ocher, 10 parts, by weight; chrome yellow, dark, 1/2 part, by weight; varnish, 30 parts, by weight; benzine, 1/2 part, by weight.
XX.—Chocolate.—Umber, 10 parts, by weight; Florentine lake, 1/8 part, by weight; varnish, 25 parts, by weight; benzine, 1/2 part, by weight.
XXI.—Terra Cotta.—Chrome yellow, pale, 10 parts, by weight; Turkey red, dark, 3 parts, by weight; varnish, 35 parts, by weight.
XXII.—Olive, Greenish.—French ocher, 5 parts, by weight; Paris blue, 1/2 part, by weight; graphite, 1/2 part, by weight; varnish, 25 parts, by weight; lithopone, 5 parts, by weight.
XXIII.—Olive, Brownish.—Chrome orange, 5 parts, by weight; Paris blue, 2 parts, by weight; lead sulphate, 10 parts, by weight; English red, 1 part, by weight; varnish, 40 parts, by weight; benzine, 1 1/2 parts, by weight.
XXIV.—Olive, Reddish.—Turkey red, dark, 75 parts, by weight; sap green, 75 parts, by weight; ocher, pale, 5 parts, by weight; varnish, 300 parts, by weight; benzine, 1 1/2 parts, by weight.
Engravers’ Varnishes.
In copper-plate engraving the plate must be covered with a dark-colored coating which, though entirely unaffected by the etching fluid, must be soft enough to allow the finest lines to be drawn with the needle and must also be susceptible of complete and easy removal when the etching is finished. Varnishes which possess these properties are called “etching grounds.” They are made according to various formulas, but in all cases the principal ingredient is asphalt, of which only the best natural varieties are suitable for this purpose. Another common ingredient is beeswax, or tallow.