Galleries, museums, photographers, artists, archivists and decorators will appreciate this 15 pack of 20 x 24" 4-Ply Pearl White Conservation Mat Board from Archival Methods. Each board is made of alpha-cellulose pulp from purified wood fiber. An economical alternative to cotton pulp boards, Conservation boards share similar surface and cutting characteristics. Purified wood fiber is recognized as being safe to use with paper artwork, photographs and documents. For archival use, the boards are acid and lignin-free with alkaline or neutral sizing. In addition the boards are buffered with calcium carbonate for added protection and longer life and made without optical brightening agents. The pearl white color is characterized by a warmer tonality than bright white museum board and is less yellow than antique white.