I have had 3 brothers,they don't care gutterman, C & C, mettler, sulky, connecting threads. Just make sure its the same in bobbin and top. That is the key with thread. The size should be on the end of the spools it should look something like 50/3(50 weight 3 ply). I wouldn't use lower than a 50 to piece. What I did in the beginning was write down my thread type and tension settings and kind of keep like a journal, it really helped me to get to know the ins and outs of my machine. A machine should be able to use most threads unless they are hand quilting or really thick you might need to really loosen your settings or have a special bobbin case. You machine should be able to use any thread. I haven't had a picky brother yet