[L. papyrus.] Paper may be described as thin layers of fine vegetable fibre. It is made from the following materials : linen and cotton rags, refuse flax and hemp, jute, esparto grass, straw, soft wood, and waste paper. In America so considerable a quantity of wood is used that it is said the spruce is being depleted from many forests for this purpose. Esparto grass which grows in the south of Spain and the north of Africa, is the staple fibre used in Britain in the production of machine-made printing and ordinary writing-paper. Writing and printing papers can be made on the same machine, but their composition and character are totally different. Printing-papers require to be comparatively soft, open, and spongy, so as to absorb the ink freely ; whereas writing-papers require to be stiff, hard, and non-absorbent. The best writing-paper is made wholly from rags, but very good is made from combinations of rags, wood, straw, or esparto. Names or devices or watermarks are put on the paper while it is traveling, in the form of half moist pulp, upon the "wire" of the paper-making machine. A light spider-ringed roll, covered with wire-gauze, and having the name or device projecting from its surface, is made to revolve upon the top of the pulp, leaving its stamp or impression upon it; the water at the same moment being immediately withdrawn, leaves the depression permanent, and thus water-marks are simply thin portions of the sheet, varying in outline as letter or device stamps itself upon the pulp on the machine. The webs of paper from the machine are then cut into sheets of different length and width as required, and examined for imperfections. The recent development of book illustration requires a highly-finished paper, which is passed through a slight mist or fine spray and then run through a super calender. Writing-paper is glazed under heavy pressure between sheets of copper or zinc.