Make strong separate solutions in hot water of gum arabic 2 parts by weight, starch 6, alum 1. Mix, and whilst moderately hot, give the paper two or three coats with a brush, allowing each coat to dry before the next is applied; finish by pressing. Another plan is to smear the paper with several cold coats of thin size, and then use solutions of white starch and gamboge water, allowing each coat to dry as before. Paper thus prepared is written on with litho. transfer ink, the back wetted, placed on a clean stone, and run through the press, when a reverse copy is obtained, which can be printed from in the usual way. (See also ii. 393.)