I made a "book" using a preprinted pillow print, about 16 or 18 inches square. Sewed it to another piece of coordinating fabric to make a "cover" and quilted it. Then cut kind of a slick white fabric (think it had some polyester in it, just a scrap, any smooth fabric will do) into squares just 1/2 inch smaller than the cover, and a good coated polyester batting that same sizes. Alternate the white fabric and the batting so you can put your pieces or blocks between the layers and the batting will hold them and the white fabric will peel off so that you don't lose pieces or mess up your blocks. It can be stored flat or rolled up and tied and your blocks/pieces will stay put.