of mechanical wood, but there should be little if any mineral matter present, as strength is an important feature. The finish of the papers is smooth, moderately rough, or rough; the colours tend to browns, greys, slates, and dark greens, but a fair number of more delicate shades can be obtained, and some of the reds are most effective. The substances of cover papers run from 18 Ib. to 56 Ib. demy per ream of 480 sheets, so there is sufficient variety from which to select paper to suit any job.
As covers for booklets, price lists, pamphlets, etc., cover papers are regularly used, and for other purposes there has arisen a demand for the darker shades. The army of photographers, professional and amateur, have employed cover papers as mounts, either in the form of cut mounts or as photographic albums. For these purposes the range of substances has been extended, the heavy papers being made in card thicknesses. In making papers for photographic mounts a very necessary quality is that the paper shall be absolutely free from chemical substances likely to affect the photographic prints mounted upon them. Colour prints are mounted on neutral cover papers for insertion in magazines or books, but when publications have extensive and growing circulations, the time and cost of mounting militate against this very effective method of displaying illustrations.
Embossed cover papers are made and finished in the usual manner, and run through special rolls having the pattern engraved upon them. Papers for embossing must possess good strength or the embossed design will not stand handling, or the paper may break when embossed.
Pamphlet cover papers are thick tinted papers, made in a very pleasing variety, serving as programme
