The 15.5" unfinished is the size of the block once you put all the smaller squares together to make the single large block.
The finished 15" measurement would be once the block is sewn to other blocks using each of the 4 edges/sides, (with exception to the blocks that are only sewn to other blocks on three sides - then that block would be 15.25 inches in one direction and 15" in the other direction. And then, adding the binding or putting on a border would cover that last .25" So when the quilt is completed, all the blocks should measure 15"
Last edited by quiltsfor; 10-15-2022 at 07:05 AM.