I am trying to make a very simple log cabin lap throw using the pattern from Nancy Zieman's Book, Quilt With Confidence. The block calls for a 4 1/2" center and each log is 2 1/2". There are two rows of dark fabric and two rows of lighter fabric. The finished size is "supposed" to be 12 1/2" but hard as I try I just can't get that to happen. Now my question is, how much would I have to add to the center piece and each of the rows in order to get a 12 1/2" finished block after I squared up the block. It just seems like I can get a finished 12 1/2" block by squaring it up to the size rather than trying to cut and sew together so that when I am finished I have a 12 1/2" block. I just finished one and all of the blocks are just slightly off but in order to square up the block I need to take it down to a finished 12" block when I would really rather have a 12 1/2" block.