The proofs having been finally read, revised, and marked O. K., the pages are sent to the foundry or to press, as the case may be.
But the proof-reader has not done with them yet. If the book is electrotyped, the plates may turn out faulty; sometimes the type will sink in places under the enormous pressure applied in moulding. It is therefore highly advisable that proofs should be taken of the plates and gone over for imperfections; this may save valuable time later when the book is on the press. Some authors don't mind the expense of making changes in their work even after the pages are cast.
The proof-reader only takes leave of the book when it is on the press and all is ready to go ahead and print. A sheet is submitted to him which he must _visé_ for bad letters, see that nothing has fallen out in transit to the pressroom, and that the pressman has not taken out any cuts to underlay and reinserted them upside down. He will also verify the folios again (if the book is printed from plates this will be the first opportunity of doing so) and see that the pages join up to what has gone before. Here his work ends.
The word "paper" derives its name from the ancient Greek word "papyrus," the name of the material used in ancient times for writing purposes, and manufactured by the Egyptians from the papyrus plant, and which was, up to the eighth century, the best-known writing material. Probably the earliest manufacturers of paper were the Chinese, who used the mulberry tree and other like plants for this purpose, and may be called the inventors of our modern paper manufacturing, as they have practised the art of paper making for almost two thousand years.
In the ordinary book papers of to-day the materials used are largely rags and wood fibres. "Esparto," a Spanish grass, is used in England to a great extent, but it is too expensive to import to this country, and is, therefore, not used here. Many other materials could be used to advantage, such as "bagasse," the waste material of sugar cane, and corn stalks, both of which make good book paper; also hemp, wild clover, and other plants which have a good fibre.
Only two kinds of rags are used, linen and cotton, of both of which there are several grades. Linen rags make a very strong paper, and are mostly used in manufacturing fine writing papers, ledgers, and covers for books where strength is necessary. Cotton rags may be divided into three distinct kinds, whites, blues, and colors, and these in turn are subdivided into several grades. Most of the blue rags are now imported from Germany, Belgium, and France; none from Japan as formerly. The whites and colors are bought in this country.