Like other articles of the commercial world, papers take their names from varying circumstances, and there is a large class whose designations have been derived from the materials or processes employed in their manufacture, as well as from the purposes for which they are to be used. ♦Coated paper♦ Coated paper, or paper having an enameled surface, is made by applying a mixture of clay and glue to ordinary paper. When referred to in connection with coated paper, this ordinary paper is called raw stock or body paper. It is manufactured in the regular way, but is made slack-sized and sent to the coating factory in web or roll form, and before it has been calendered. The clay used is pure kaolin or china clay, formed by the disintegration of feldspathic rock. The clay is largely found near Cornwall, England, and the pure white variety, principally used, is known as leemore clay, while the finest is called blanc fixe. The clay is ground to the fineness of fine wheat flour and mixed into solution of about the consistency of milk. Its purpose in the paper-coating process is to cover the body paper, giving it an even surface, susceptible of a high and glossy finish. The glue used is of the ordinary sort so well known in the regular market. Its presence renders the clay solution very adhesive when applied to the body paper. ♦Extreme smoothness required♦ The cost of illustrations having been greatly reduced through the perfection of photogravure or half-tone processes, a large and increasing demand exists for a paper of extremely smooth, firm, and sensitive surface, suitable for the reproduction of the finest half-tone cuts; a paper with such delicate fineness and susceptibility that the minute lines of a photogravure cut--so minute in instances as to be indistinguishable to the touch of the finger--will be perfectly reproduced when printed upon its enameled surface. Large factories are devoted entirely to the coating process. They do not necessarily make their own body paper, but frequently purchase it from outside sources. At first, this clay solution was carried to and spread upon the surface of paper by the use of a fine hair brush. This was applied to one side or surface of the paper at a time, the same process being repeated on the opposite side, if both were to be coated. Since its earlier introduction, the process of surface-coating paper has undergone great improvement, and the method to-day in vogue, while seemingly complete and exceedingly rapid, is yet readily understood, and the machinery required is quite simple. This consists of: ♦Parts of coating machine♦ First--A vat, to hold the enameling solution. Second--Rollers, to regulate its distribution upon the web of paper. Third--Brushes, to work out small lumpy particles and overcome any tendency to unevenness of coating. Fourth--An automatic carrier, to convey the coated web through a drying-room; after which it is calendered to the surface wanted and cut into sizes required.