Page:Paper and Its Uses.djvu/17

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RAW MATERIALS
5

the stem of the hemp plant, and the papermaker receives it in the form of old ropes and string. The dimensions and properties of the fibre are similar to those of the fibre of linen. Jute is the inner bark of an Indian plant, producing fibres 1/10 of an inch in length by 1/1000 of an inch in diameter. The fibre is smooth, difficult to bleach, but the resulting paper is strong and tough. The fibre of the manilla hemp is not as long as the ordinary hemp, being about 1/4 of an inch by 1/1000 of an inch, cannot be bleached to a good white, so a white manilla paper is considerably lower in colour than other white papers. Manilla paper is, however, very tough and strong, and though a large quantity of "manilla" paper is made entirely of wood pulp, there is a great difference between the real and the imitation.

The fibres from straw are small, only about 1/16 of an inch by 1/2000 of an inch, and consequently straw papers are much weaker than those made from longer and broader fibres, but, as an admixture, straw still finds a place in writing papers, giving translucency and rattle. Esparto fibres are also very short and fine, about 1/40 to 1/16 of an inch by 1/2000 of an inch, making a light bulky paper when used by itself, and blended with other materials—with rags for good writings, and with chemical wood for fine printings and litho. papers—to impart special characteristics, such as opacity and softness, which may be lacking in the other fibres. The well-known featherweight papers, used for bulky volumes of fiction, are frequently manufactured from esparto fibre alone.

The fibres of the various wood pulps vary considerably in length, breadth, and thickness, being from 1/25 of an inch to 1/8 of an inch long, and generally very thin. Fibres of various shapes are met with in wood pulps, some not unlike linen fibres, but many others so distinct as to be unlike all those that have been