You can now get the quality and preservation characteristics of traditional cotton backs in a modern, foam core product.  1/8 inch foam core with truely archival foam and archival cotton rag facing papers on both sides.  Preservation and rigidity as well as resistance to warping caused by changing environments.  Cotton covering is buffered.  Our biggest sellers are foam core and cotton rag mats.  This combinaton works great when showing your work in our super clear bags. The foam core provides the rigidity needed when not using a picture frame. A wonderful traditional adaptation to modern manufacturing.