Colorplast is still much more expensive than simply purchasing styrofoam board. I purchase it at my Dollar Tree store for 1.00 a sheet and get 10 boards out of each one. It comes in a 20"X30" sheet. They are strong enough to do the job and I have never cut my hand on them as I have done with the sharp edges of Colorplast. It is acid free also.
Ann in TN