Here's an innovative streatch thread that allows you to sew seams that give using a normal lock stitch or straight stitch on a conventional sewing machine, or an overcast stitch on a serger. This thread is ideal for top and bottom thread. Perfect for leotards, gym clothes, swimwear, sportswear, activewear and stretch denim. Each spool contains 225 yards of thread and is colorfast even with chlorinated water. Now don't be hesitant. Go play with your sewing machine or serger testing out this threads potential. Go tackle those knits and make some of those comfy garments we all like to live in. Probably not sewing a swim suit for myself (I'll stick to shorts) but for the kids and grandkids for sure. Happy sewing on those comfy knits. I use a blue floss threader to pull through the eye of my sewing machine. And I use a size 14 stretch or yellow band needle. Works great and the straight stitch seam gives nicely.