The foregoing directions are, with very little differences, to be observed in making all sorts of copal varnishes, excepting the quantities of oil, gum, etc., a few of which will be now added.

Copal Varnish For Fine: Paintings, etc

Fuse eight pounds of the very cleanest pale African gum copal, and, when completely run fluid, pour in two gallons of hot oil; let it boil until it will string very strong; and in about fifteen minutes, or while it is yet very hot, pour in three gallons of turpentine, got from the top of a cistern. Perhaps during the mixing a considerable quantity of the turpentine will escape, but the varnish will be so much the brighter, transparent, and fluid; and will work freer, dry quickly, and be very solid and durable when dry. After the varnish has been strained, it" it is found too thick, before it is quite cold, heal as much turpentine and mix with it as will bring it to a proper consistence.

Artist's Virgin Copal

From a select parcel of scraped African gum copal, before it is broken, pick out the very fine transparent pieces, which appear round and pale, like drops of crystal; break these very small; dry them in the sun, or by a very gentle fire. Afterwards, when cool, bruise or pound them into a coarse powder; then procure some broken bottles or flint-glass, and boil the same in soft water and soda; then bruise it into a coarse powder, like the gum; boil it a second time, and strain the water from it, washing it with three or four waters, that it may be perfectly clean and free from grease or any impurity; dry it before the fire, or upon a plate set in an oven. When thoroughly dry, mix two pounds of the powdered glass with three pounds of the powdered copal; after mixing them well, put them into the gum-pot, and fuse the gum; keep stirring all the time; the glass will prevent the gum from adhering together, so that a very moderate fire will cause the gum to fuse. When it appears sufficiently run, have ready three quarts of clarified oil, very hot, to pour in. Afterwards, let it boil until it strings freely between the fingers. Begin and mix it rather hotter than if it were body varnish, for, as there is but a small quantity, it will be sooner cold; pour in five quarts of old turpentine, strain it immediately, and pour it into an open jar, or large glass bottle; expose it to the air and light, but keep it both from the sun and moisture until it is of a sufficient age for use. This is the finest copal varnish for fine paintings.

Cabinet Varnish

Fuse seven pounds of very fine African gumcopal; when well dissolved, pour in half a gallon of pale clarified oil; and when clear mix with it three gallons of turpentine; afterwards strain it, and put it aside for use. This, if properly boiled, will dry in ten minutes; but if too strongly boiled, will not mix at all with the turpentine; and sometimes, when boiled with the turpentine will mix, and yet refuse to amalgamate with any other varnish less boiled than itself; therefore, it requires a nicety which is only to be learned from practice. This varnish is very apt to chill all other oil varnishes to which it may be added, and is principally employed as a quick dryi+ng varnish for the occasional use of japanners, cabinet, and coach-painters. Cabinet varnish is, however, more generally made with anime than copal.