Not sure what brand machine you have...I have Husqvarna Viking, SE and use ONLY European made threads as is recomended for European made machines. Reason bing, Europan made machines are calibrated or watever for those particular threads and the way they are made. Also, itmakes a differencesometimes on the design you are making as to the weight ofthe thread and the type. Sometimes Sulky works great and sometimes Robison Anton works well and etc. I have a grand mixture and sometimes it depends on availability of thread and color. I think it's a personal preference thing. Good Luck