Enamel colors which dry quickly, but remain elastic so that applied on tin they will stand stamping without cracking off, can be produced as follows:

In a closed stirrer or rolling cask place 21.5 parts, by weight, of finely powdered pale French rosin, 24.5 parts, by weight, of Manila copal, as well as 35 parts, by weight, of denaturized spirit (95 per cent), causing the cask or the stirrer to rotate until all the gum has completely dissolved, which, according to the temperature of the room in which the stirrer is and the hardness of the gums, requires 24 to 48 hours. When the gums are entirely dissolved add to the mixture a solution of 21.5 parts, by weight, of Venice oil turpentine in 0.025 parts, by weight, of denaturized spirit of 95 per cent, allowing the stirrer to run another 2 to 3 hours. For the purpose of removing any impurities present or any undissolved rosin from the varnish, it is poured through a hair sieve or through a threefold layer of fine muslin (organdie) into suitable tin vessels or zinc-lined barrels for further clarification. After 10 to 14 days the varnish is ready for use. By grinding this varnish with the corresponding dry pigments the desired shades of color may be obtained; but it is well to remark that chemically pure zinc white cannot be used with advantage because it thickens and loses its covering power. The grinding is best carried out twice on an ordinary funnel mill. Following are some recipes:

I

Enamel White. — Lithopone, 2. parts, by weight; white lead, purest, 0.5 part, by weight; varnish, 20 parts, by weight.

II

Enamel Black.—Ivory black, 2 parts, by weight; Paris blue, 0.01 part, by weight; varnish, 23 parts, by weight.

III

Pale Gray.—Graphite, 2 parts, by weight; ultramarine, 0.01 part, by weight; lithopone, 40 parts, by weight; varnish, 100 parts, by weight.

IV

Dark Gray.—Graphite, 3 parts, by weight; ivory black, 2 parts, by weight; lithopone, 40 parts, by weight; varnish, 110 parts, by weight.

V

Chrome Yellow, Pale.—Chrome

yellow, 2 parts, by weight; lithopone, 2 parts, by weight; varnish, 40 parts, by weight; benzine, 1.5 parts, by weight.

VI

Chrome Yellow, Dark.—Chrome yellow, dark, 2 parts, by weight; chrome orange, 1/8 part, by weight; lithopone, 1 part, by weight; varnish, 35 parts, by weight; benzine, 1 part, by weight.

VII

Pink, Pale.—Carmine, 0.5 part, by weight; lithopone, 15 parts, by weight; varnish, 40 parts, by weight; benzine, 1.5 parts, by weight.