All of the pieces in the top that I just finished were 1" wide, finished- supposedly. The actual dimensions of my quilt were noticably smaller than what it theoretically should have been, because there were so many pieces. If you take a tiny bit off of a whole lot of pieces, it does add up. It didn't matter for my quilt, but I suppose that if you were making a quilt with blocks that some had a lot of little pieces, alternating with blocks of a solid piece of fabric, for instance, there would be a discrepancy in the sizes of the blocks.