I use to stock Gilman Bros 1/8" foamboards, but they were always badly warped. This time, when i needed to restock foamboards i ordered the 3/16" as a few of you have suggested a while back. The sheets were not perfectly flat, but good enough... much better than the 1/8" thick. I started using the 3/16 about a month ago... no problems, then, something bad happened. A customer brought in a 24 x 30 aerial photo and asks me to be very careful because it is a pretty expensive photo ($300.00). I helped him choose the matbards, frame, glass, etc. and suggested it be mounted on a foamboard to keep it flat... he agreed. Right after he left, i mounted it on a Gilman Bros 3/16" foam board. When i removed it from mounting equipment, i was extremely disappointed... there was one huge bubble almost in the center of the photo. Oh cr*p !, what do i do? If this should ever happen to you, try this, it worked for me: The photo is mounted on a thin layer of paper which is mounted to the "foam" in the foamboard. Peel the layer of paper away from the foam carefully and slowly (I was able to remove it without creating any creases). Now, remount it to another sheet of foamboard, BUT, if you stock Gilman Bros foamboard, mount it to a matboard instead, to be on the safe side. Since this happened, I HAVE mounted photos, posters, etc. to Gilman Bros. foamboards with not problems yet,(maybe that was one bad sheet), but i dread doing so. The next time i restock foamboards it will NOT be Gilman Bros foamboard!!!!!!!!!!!!!