I love the boards. I bought the cheaper (acid free) on one side. I found that for larger yardages (like 4 yds) or more that they tended to be flemsy. I purchase some foam boards (8 1/2 x 11) from Uline for about 70 cents each for the larger yardages of fabric. More expensive but they may great bracers on the shelves. I will order more. Mine are not acid free but the acid free are available....just much more expensive. What happens if the boards are not acid free? I am not familiar with the failure of the non-acid free boards.