Actually this is what I did: I sewed my strips (2 1/2 inches x WOF) together and pressed the seams. Then I measured the width of the sewed and pressed piece. I then cut my blocks that same measurement. That makes a square block a la Mary Ellen Hopkins. As she would say "It is your measurement." So if your 1/4 inch seam is "off" your block is still square. I haven't read the whole thread (I know this bugs some people, sorry) so I apologize if I repeat.