they can be the corner triangles, or any other little piece of scrap fabric, it is easiest to use a foundation when working with small scraps, i usually cut muslin into 12-13" squares and sew my crumbs in the stitch and flip technique to the foundation, when the foundation is covered i trim and square it to about a 10 1/2" block...and those strips i cut off, if they are 1" or wider i set them aside then sew them together to make more crumb/string blocks. :thumbup: