My Janome 6600 P will use any thread I have tried. I use lots of WalMart Coats & Clark. Just have to use a brush to clean under the plate every time I change the bobbin. If lent builds up on the needle, I clean under the plate. Seems like it needs cleaning more frequently than my old 1967 Fleetwood used to require. It is okay, I love to pet my sweet "Jan".