I'm thinking 4 1/2 inches. 4.5 x 3= 13.5 less 1 inch for two seams (.25 x 4) should give you 12.5; 12 inch finished. I looked at a quilter's cache pattern.
I'm thinking 4 1/2 inches. 4.5 x 3= 13.5 less 1 inch for two seams (.25 x 4) should give you 12.5; 12 inch finished. I looked at a quilter's cache pattern.