There are some older threads on this subject, but rather than bump an old thread I'm making a new post as the old threads didn't really answer the questions I have. For the past couple of years I have been using corrugated plastic as my target backers on top of plywood sheeting. I need the plywood to provide the mechanical strength, limit wind flex of the corrugated plastic, and withstand high winds on target boards that are out in the elements all year long. My 100 yd. target board is 48" wide and 32" tall to provide the 'real estate' needed to mount several targets at one time. This has worked very well as the corrugated plastic is fairly cheap, easy to obtain, and can be replaced as needed. The plywood backer behind the corrugated plastic splinters and is more expensive to replace. Related threads mentioned Homosote, and I'm wondering if this stuff would be an alternative to the plywood I now use behind my corrugated plastic? It comes in 4 x 8 ft. sheets and is much cheaper than plywood. Will it stand up to weather all year long? Will it provide the mechanical strength to limit wind flex during shooting sessions and survive high winds?