Nielsen & Bainbridge Smooth Mount Foam Board (40 x 60", 20-Pack)

The 20-pack of 40 x 60" Smooth Mount Foam Board from Nielsen & Bainbridge is a 1/4"-thick warp-resistant board, and its surface has been coated with a neutral pH white clay. Both the paper and foam have been bonded through a special thermal process, and the foam is made of an extruded polystyrene.