I bought mine from Amazon. I didn't worry too much about acid free on both sides or not. That was several years ago and none of the fabrics that I've pulled to use shows any sign of being stained or damaged by being on boards that weren't acid-free on both sides. I bought the regular size, I think it was as little larger than 10x7. I cut them to the size I need to manage my fabric and also fit in my drawer units. I've got some that have 3 or more yards of fabric on them. Others have as little as a fat quarter. I've even started wrapping my smaller than a fat quarter but too big to cut scraps around them and standing them in the drawer and that has helped a lot- both with controlling the mess and with helping me use those scraps up since I can see at a glance what is in my scrap drawers now.