I am not trying to fight, just to clarify. With this block you join two 6.75in blocks and you get 6.5 x 13 rectangle, join two of those you get 13 in unfinished square or 12.5 inch finished block.
Originally Posted by Jim
6.75 + 6.75 = 13.5 - .5(both .25 seam allowances) = 13 which would be wrong
6.5 + 6.5 = 13 - .5 = 12.5 which would be the correct measurements needed