I forget where I about this *One Neat Trick*, but I got to try it out myself when I was hand sewing the swing cushions closed. Some (but not all) spools of thread apparently unscrew at the base and have an interior place to keep your needle. This was a spool of Gütermann outdoor thread. It was pretty cool to have this option to keep track of my needle when I wasn't in my sewing room! So, I was glad to find this out and now you know too.