The Library Binding Institute specifications for endpapers used in library binding call for a paper having a tensile strength in the machine direction of not less than 44 pounds (1 inch strip and in the cross direction of not less than 25 pounds (1 inch strip) for 60 pound basis weight paper (24 x 36-500)
2. In leather, tensile strength is defined as the force per unit area of cross section required to produce failure. Numerous factors affect the tensile strength of any given leather, including the kind of tannage, the length of the tannage, the species and age of the animal, the degree of splitting, and so on. Most leathers will show a tensile strength of between 2,000 and 6.000 pounds per square inch. (17 , 209 , 363 )