it looks like you can modify it to 2 inch squares to get your 12 inch block. the 4 patches in the corners would be 4 inches by 4 inches, or 2 inch squares. The large blue centers with half squares would also be 4 by 4. And the center block would be 4 by 4. All finished sizes of course. Add the 1/2 inch for seam allowances.