Originally Posted by amma
Each block in the 9 patch is cut 4 1/2" :D:D:D
Which makes a 12 1/2 inch 9 patch. You reduce it by another half an inch when you make it a disappearing 9 patch. So that makes it a 12 inch unfinshed block and only and 11 1/2 inch finished block. A half an inch does not divide well by 3.