Originally Posted by Synnove

Yes, that's correct. Three 2.5 inch blocks across, sewn together side by side, equals a width of 6.5 inches. Finished comes to 6 inches. Draw yourself a picture of a row of blocks, separated from each other by a space. Then in the spaces write down each seam allowance. The total will be 7.5 inches, which becomes 6.5 inches when everything is sewn together. This finishes at 6".