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are so many varieties of paper which are only occasionally encountered that it is better to present the whole of them in alphabetical arrangement (see Chapter XVII.), and in this section to give a longer description of a few representative papers.

Blottings and filter papers are very similar in appearance and manufacture, their definite purposes being to absorb moisture, and to filter suspended matter from solutions respectively. The description of blotting paper manufacture will cover both varieties. The office of blotting paper being to absorb ink, the raw material is chosen with a view to obtain the most efficient fibre for the purpose, soft muslins, too soft for writing papers, making excellent blottings. The preliminary treatment of the rags has been described already. Beating is carried out as quickly as possible, sharp knives being used to cut the fibres into short lengths, and not to bruise or beat the fibres more finely. As many fibre ends as possible must be absorbing on a given area at one time, and the shorter the lengths to which the fibres are cut, the greater the efficiency of the blotting paper, within certain limits. Certain after-treatment of the fibre is resorted to, to produce as soft and absorbent a