Hi, I am in the process of finishing up some large prints that will be mounted on 40x48 4-ply mat board. I know I will need to buy 40x60 mat board and was wondering if anyone here has a good source for this larger size board that doesn't charge a fortune for shipping? Also, I will need to transport the prints once matted to their destination and need some type of solution for protecting the prints. The size of the finished print with mat is 40x48. Thanks for your tips and info in advance.