We can apply PVC backer board to the back of your foam board(s) to add rigidity to the foam. This is helpful for mounting foam board vertically or ensuring the foam lies flat and secure on a table.
We use black PVC for our backer board because, like the foam, it is not affected by moisture and can be easily cleaned.
Black PVC backer board is available in 1/8", 1/4", and 1/2" thick.