My old Brother machine was not picky at all. It liked anything I put in it. My new Viking likes Mettler and Gutterman. I used to sew with Sulky thread but the new guy doesn't like it at all. Gutterman is not to pricey with Jo Ann's coupons. I haven't tried Coats & Clark in the new machine yet, but it was all my Mom ever used and she never had problems. She did mostly sew garments though, maybe that makes a difference.