Compositions and methods for manufacturing sheets having a highly inorganically filled matrix. Suitable inorganically filled mixtures are prepared by mixing together an organic polymer binder, water, one or more inorganic aggregate materials, fibers, and optional admixtures in the correct proportions...http://www.google.com/patents/US5508072?utm_source=gb-gplus-sharePatent US5508072 - Sheets having a highly inorganically filled organic polymer matrix
