THICKNESS, TENSILE STRENGTH AND WEIGHT

The thickness of the finished fabric shall not exceed 0.30 millimeter (0.012 inch) or be less than 0.20 millimeter (0.008 inch). The tensile strength of the gray cloth shall be not less than 18 kilograms per centimeter (100 pounds per inch) of width in the warp, and 9 kilograms per centimeter (50 pounds per inch) in the weft. The average value for the warp and weft in the finished fabric must show an increase over the average value for the warp and weft in the gray cloth of at least 10 per cent of the strength of the gray cloth.

The finished fabric, when dry, shall weigh not more than 250 grams per square meter (0.5 pound per yard), or less than 200 grams per square meter (0.4 pound per yard).

ABSORPTION OF MOISTURE

At a normal relative humidity of 65 per cent it shall not absorb more than 5 per cent of moisture, or expand (an average of both directions) to exceed 0.45 per cent, and when subjected in a closed case to a saturated atmosphere for two hours at a temperature of 20 C. (68 F.) shall not absorb more than 10 per cent of moisture or expand (an average of both directions) to exceed 2 per cent. All increases to be computed on the basis of the dry weight and dimensions.

FOLDING ENDURANCE

The folding endurance, as determined by the Schopper folder, shall be not less than 65,000 double folds for the warp and not less than 10,000 for the weft.

COLOR

Before coating, the fabric must be dyed with a purely mineral or inorganic color (such as iron salts), so as to imitate the color of the finished cloth, but somewhat lighter in shade, so as to give the desired "linen" effect. All coal-tar, aniline, vegetable, or other organic dyes and lakes must be strictly excluded from both fabric and coating, even in traces; except where necessary to match color, lake may be used in red, blue, or brown. The following substances must be also excluded: Chrome yellow and other chromates, ultramarine, browns containing bituminous or other organic matter, compounds of lead and a.r.s.enic.

The color of the finished fabric should be slightly darker than the standard sample, which will be furnished on application, and it must not show the slightest change of color after exposure under prescribed conditions to direct sunlight, or to the action of ammonia gas, sulphuretted-hydrogen gas, sulphur-dioxide gas, or illuminating gas.

RESISTANCE TO MOLD AND INSECTS

The finished fabric shall be immune to the growth of mold or the attack of insects.

TESTS

Physical and chemical tests to verify the properties required by these specifications will be made according to the "Standard method for testing book cloths" as used by the Bureau of Standards, copies of which can be obtained on application.

APPENDIX B

READING LIST ON BINDING

Adam, Paul. Practical bookbinding. 1903. Van Nostrand. $1.25.

A translation of a German work.

American library a.s.sociation. Committee on bookbinding. Binding for libraries. 1915. A. L. A. Publishing Board. $.15. (Library handbook No.

5. Second edition, revised.)

Binding specifications which may be used by large as well as small libraries.

Bailey, A. L. Bookbinding. 1911. A. L. A. Publishing Board. $.10.

Preprint of Manual of library economy, Chapter 26.

Bindery talk. 1912-13. v. 1-2. All published.

A periodical published by W. E. Reavis, Los Angeles, California, covering various phases of library binding.

Bliss, H. E. Better bookbinding for libraries. Library Journal, 1905, 30:849-57.

Brief article on methods and materials.

Brown, J. D. Bookbinding and repairing. In his Manual of library economy, pp. 328-48.

Valuable chiefly for its section on lettering.

Brown, M. W. Mending and repair of books. A. L. A. Publishing Board.

$.15. (Library handbook No. 6.)

Caldwell, M. R. Preparing for the binder. Public Libraries, 1906, 11:302-3.

Chivers, Cedric. Paper and binding of lending library books. American Library a.s.sociation. Bulletin. 1909, 3:231-59.

Also published separately by Mr. Chivers. A record of experiments and tests of modern book papers.

Chivers, Cedric. Relative value of leathers and other binding materials.

1911. Published by the author.

A record of tests of leathers. Practically the same article will be found in the Bulletin of the American Library a.s.sociation for 1911, p. 164.

c.o.c.kerell, Douglas. Bookbinding and the care of books. 1902. Appleton.

$1.25.

Best general book on binding processes, but does not cover all library requirements.

Coutts, H. T., and Stephen, G. A. Manual of library bookbinding. 1911.

Libraco Limited. 7s. 6d. net.

A valuable book for all libraries. Gives the English point of view.

Crane, W. J. E. Bookbinding for amateurs. 1903. Scribner. $.65.

Cundall, Joseph, ed. On bookbindings, ancient and modern. 1881. Bell, Lond. $12.

Will be used mainly by those interested in the history and artistic side of bookbinding.

Dana, J. C. Notes on bookbinding for libraries. Ed. 2. 1910. Library Bureau. $1.