Check out the "Sew Easy!" Group here at Thingiverse. It is all about sewing supplies, 3D printed fashion and tools related to threads and fabric http://www.thingiverse.com/groups/sew-easy"
This is a clip to keep bobbin thread spools from untangling. Make sure to print it in a more flexible material than PLA (I used Nylon, this is still strong enough and yet flexible to fit the clips easily).