Also called index bristol, a lightweight cardboard, or paper grade characterized by high stiffness and thickness, as well as possessing a high degree of receptivity to writing inks. Index stock is typically used for index cards, but has a wide variety of usage whenever a low-cost, but stiff and attractive paper is required. Is available in smooth finish or vellum finish, and is manufactured entirely from chemical pulp.
The basic size of index stock is 25H x 30H, and has basis weights of 90, 110, 140, and 170-pound. Standard sizes are 20H x 24I, 22H x 28H, 22H x 35, and 25H x 30H.