Interesting. My Viking Platinum defaults to a 'tight woven' fabric. I've only had to change this the last day or so when I got a piece of thread stuck somewhere in the threading slots. Then I went to 'medium woven' to deal with the intersecting seams not breaking my thread. I think I've finally gotten out the piece of thread. Machine is about 5-6 years old. And I love it. That said, I use whatever thread I have. I currently have a kitty litter bucket full of thread that is of questionable age but is working just fine. I also use cheap serger cone thread from Joann's for piecing. I hand quilt so for that I do use 100% cotton 'hand quilting' thread but that's the only time I'm picky. Have yet to have an issue with any type of thread either in the machine or holding up with wear.