Paper with a minimum gloss and reflectance of light is a factor for easy reading. When using the letterpress process, however, a high finish or levelness of surface is vital to the sharp reproduction of cuts. English Finish and semi-dull Coated papers give the maximum of reproduction without objectionable reflectance. For the lithographic process high finish is not necessary, but again, tends to increase the sharpness of detail. For the gravure process the same is true.

2. Opacity

Good opacity is desirable, and in the medium and heavy weights should be no problem. In the lighter weights much depends upon the type of paper selected. The introduction of special materials to increase opacity has produced special papers for this purpose.

3. Grain direction

In all Book paper made on a paper machine, the majority of the fibers run in one direction. Hence we have the terms "with" and "against" grain. Such paper is stronger when torn crossgrain and folds smoother with grain. In general, paper is ordered with the grain running the length of the sheets for all purposes. In the folder, booklet, or bound book the grain should run parallel to the fold or binding. This gives a smoother folded edge and the pages, being more flexible, lie flatter.

B. F Perkins 6t Son, Inc., Holyoke, Mati.

Perkins Pressure Bulker to Measure the Bulk of Sheets of Paper.

1. The diameter of the pressure foot is

three square inches and the pressure is figured in pounds per square inch of paper.