If I'm cutting HST's, I ALWAYS go up to a full measurement - 2 7/8th I would cut at 3", 4 7/8" I would cut at 4", etc., etc. Then I draw a diagonal line across the lightest color square and sew 1/4 " on either side. I would then press to the dark side and recut to the correct final measurement. It's an extra step, but I'm much happier with my blocks, as after all these years I have not completely mastered the scant 1/4 ", so I'd rather cut twice and get the right size.