1/8 thick foam board is perfect all general photo mounting purposes or as a rigid backing board. Purchase this foam board online from
POP! 6mm Extra Thick Foam Sheet 9x12
Golden State Art,Pack of 200, 8x10 White Foam Board Backing 1/8
22 x 28 Wide Foam Core Board - Foam Core Board
Pop! 6mm Extra Thick Foam Sheet 9x12 - Black - Kids Foam Sheets - Kids - Joann Fabric and Craft Stores
Shop Flap Seal Mailing or Art Sleeves 9x12 Size
Foamboard - Black/Black - 4' x 8' x 1/2 - Set Shop NYC
WA Portman 9x12 Craft Knife & Ruler Mat Set - The Art Store/Commercial Art Supply
Viewpoint Acid-Free Black Foam Backing 8x10 is 1/8 thick and easy to cut. Perfect for displays, protecting the back of a frame, or a hundred other
Viewpoint Acid-Free Black Foam Backing 8x10, 1/8 Thick 5 Pack
Archival Methods Acid Free Foamboard, 17x22 1/8 Thick, Color: White, (Pack 10)