Pounce

1. "A finely ground powder, generally prepared from gum sandarac mixed with pumice or cuttlefish bone. Originally, it was used to prevent ink from spreading on unsized paper or over an erasure, as well as to prepare vellum to take writing ink."<ref name="Etherington">Roberts, Don., et al. Bookbinding and the Conservation of Books : a Dictionary of Descriptive Terminology. Library of Congress : For Sale by the Supt. of Docs., U.S. G.P.O., 1982.</ref>