I agree with others who have said that the seams will be crossed again. ALSO, backstitching causes UNneeded bulk in the seam. If you are back stitching and your making half square triangles for a pinwheel all that thread builds up and only adds to the builk in the center points! I sometimes finish a top and it lays around for awhile before I get around to quilting it, in this case I will shorten my stitch length REAL short so the stitches dont have a chance to come apart! I shorten the stich length for about 1/4 inch and then I go back to the regular length to sew the rest of the row and then at the very end the last 1/4 inch I will shorten the stitch again. This is easy for me to do because my sewing machine has a dial stitch length instead of digital. You could also leave your begining and ending tails a little longer as your putting your rows together. and then once your done quilting and your trimming up your quilt you will cut those threads off. The extra long tail doesn't allow the stiches to come out! :) HTH