So simple for stained glass and quilting.  Just 2.5 inch squares in the middle (4), 1.5 inch squares around the center 4 block, and 2 inch squares on the outside.  Using a 3/8 inch seam allowance.   Great to make a window to match a quilt.  This one I am doing now with a 3.5 inch border around the block in a contrasting color allowing for a 1/2 inch seam to fringe between blocks.  Dont know any way to "fringe" glass (ROFLOL).  I have collected all kinds of scrap material and glass which is being cut into 1.5, 2, 2.5. 3. 3.5, 4 and 4.5 inch squares. I have three possible combinations of these sizes which make a quilt block or stained glass block the same finished size.