I hand piece with Aurifil 50 weight. I use a single strand. Nothing has ever fallen apart. I use a size 9 or 10 needle. I load the needle with 3 or 4 stitches at a time. Each time I start a new load on the needle I put the needle slightly behind my last stitch so I have a little back stitch there to make my seam stronger. If you keep your stitches small strength of the seam isn't a problem. I want as thin of a needle as possible and as thin of thread to keep my seams and blocks more accurate.