Strathmore Museum Boards

Available in single ply (.0129" ± .0005" ), two-ply (.0305" ± .0015" ) and four-ply (.0610" ± .0030" ) thickness. Strathmore Museum Mounting Board successfully challenges the effects of time, as well as the environment, upon ­valued works of art. The surface is designed to deliver a smoother, cleaner cut. The colors are solid throughout the board and meet the Library of Congress Standards for Archival Properties.https://www.strathmoreartist.com/matting-museum-mounting-board/museum-mounting-board.html The four-ply is just a thicker board that might be better for stand-alone presentations, while the 2ply is the standard thickness for mounting and mat boards. I hope that this information is helpful. Please let us know if you have any other questions or concerns.