(b) Smoothness, so that there will be a comparatively small amount of friction when withdrawing a book from between two others on the shelf.
(c) Ability to withstand constant rubbing back and forth on tables.
(d) Color that is fast when exposed to light; if possible it should be fast to water also, though this is less important.
(e) Color should be dyed in the piece, not pressed in by machinery.
Many cloths have some of these qualities but few have all of them. So far as is known to the writer only the grade of cloth described on page 77 has the last qualification.
Practically all cloth used in the United States is made of cotton. The best cloths are manufactured by The Holliston Mills, Norwood, Mass.; The Interlaken Mills, New York City; The Joseph Bancroft & Sons Company, Wilmington, Del., and by the Winterbottom Company and the Manchester Book Cloth Company in England. Since a number of grades are made in several different patterns and a great number of shades for each grade and each pattern, a variety of choice is permitted. As a matter of fact, however, most librarians select a good grade with a regular weave and confine themselves to a few standard shades, such as dark green, brown, red, dark blue, and tan.
Since the strength of the warp is much greater than that of the weft, it is advisable when possible to cover books with the warp running across the cover. This, however, may entail some hardship on the binder for it may frequently happen that in order to cut his cover economically he must make the warp run lengthwise of the book. If a strong cloth is used the advantage is not great enough to be insisted upon.
Each of the American firms mentioned makes three distinct grades, all of which libraries may use. Each firm uses a different name for each grade. In other words, there are no general names which can be used for the corresponding grade in all makes. Therefore for the purposes of this chapter these cloths will be considered under the heads of Grades 1, 2 and 3, but it must be remembered that this is an arbitrary designation not known to the trade. Under each grade will be given the specific names used by the three manufacturers.
Grade one of cloth, the cheapest that a librarian may use, is not made of the best quality of cotton thread and should never be used under any circumstances for full binding. It may be used on the sides of books bound in leather; if this be done the corners should be covered with vellum, for this cloth does not withstand hard usage and is likely to fray at the corners. It is a cloth commonly used by publishers, but should be used sparingly by the librarian. "Art vellum" made by the Interlaken Mills, "Aldine vellum" made by the Holliston Mills, and "Linen finish" made by the Joseph Bancroft & Sons Company, come within this grade.