Enamelled - 1 lb. of parchment cuttings, 1/4 lb. of isinglass, and 1/4 lb. of gum arabic, in 4 gal. of water, are boiled in an iron kettle until the solution is reduced to 12 quarts; it is then removed from the fire and strained. The solution is divided into three parts of 4 quarts each; to the first portion is added 6 lb, of white-lead, ground fine in water; to the second portion is added 8 lb. of white-lead, and to the third is added 6 lb. of white-lead. The sheets of paper are stretched out upon fiat boards.and brushed over with a thin coat of the first mixture with an ordinary painters' brush; the paper is then hung up to dry for 24 hours. After this, the paper is ready to receive a coat of the second mixture, and again hung up to dry for 24 hours; the paper is then treated in the same way with the third mixture, and dried for 24 hours. After this it receives a high gloss, which is obtained by laying the work with its face downwards on a highly-polished steel plate, and then passing both with great pressure between a pair of powerful rollers. It is to be regretted that this enamelled surface is not very durable, as it comes off after wetting.
To prevent this, a solution of some resinous substance may be added in the last operation.
Incombustible paper may be made by mixing with the pulp a fluid obtained by adding to an aqueous solution containing 1 3/4 oz. of pure tallow soap, just enough alum to completely decompose the soap. The paper made with this requires no size. (See also ii. 299.)