Most spools have a split or movable piece on the bottom that can hold thread. OESD and Robison Anton have a bendable plate at the bottom of the small cones. Sulky, Madeira, have a small area between the top or bottom of the spool and the actual spool that will hold thread. If you have plain cones, the thread net or the wrap works, or you can get some scotch magic tape and tape the end to the underside of the spool.