madquilter hit it on the nose... they will be sized perfectly and lay perfectly flat... the first thing i do on any quilt is to count the number of HSTs i need, Then I separate for color, count, figure out how big a grid to draw and then sew all i need of one color, cut, press and square up every HST before proceeding. if i need a 6 (finished) i cut at 7, two seams come off and then there is still a tiny bit of trimming to do...but they will all be perfect.