I bought some C & C thread recently & it didn't have notches for securing the thread. The spool I bought had the slit all around the spool so you can slip the thread in that & spin it around to secure (don't know exactly how to describe it). However, when they make the spool, the outer edge of the spool is rough (both ends) so I had to file that down in order for my thread not to hang up on it. I think I will contact C & C & see if they can make a smoother spool.