I love making string quilts. Sometimes I use foundations, sometimes I don't. It does add a little bulk. When I string piece without foundation the first thing I do is- if the strip is WOF (width of fabric) I remove the selvege ends and cut it in half. The strips are much more managable if 21" or less in length. The next thing is that I sew then press it from the back, using starch at least once. Usually I starch from the back then again from the front. Makes the cutting more accurate and when its done it slides thru the machine much easier when quilting it. Then when the quilt is done I wash and dry it, to remove the starch and soften it up. Hope this helps.