I have been using all brands of thread, especially the cotton coated polyester, coats and clarks, any popular brand that I find at thrift stores and auctions. I have always believed to use what you have on hand, recycle, reuse, etc, especially if it works with your sewing machine. I do not use any of the off brand threads, especially when I look close and see lots of loose fibers. But I have learned so much from everyone on this board about fabric, I now look for better grades fabric, and know there is a difference some of the time between my lqs and Joann's. It is time for me to try out better grades of cotton thread and see for myself. Connecting threads has a sale on thread and I ordered some along with some clearance flannels (learned the hard way about some of the differing quality of Joann's flannel). I also ordered a spool of aurifil (orange spool) from another site. As soon as they come in, I am going to try them in my Viking Sapphire. This is the first time in years that I have bought new thread, as I find alot at yard sales and auctions over the years. I am willing to learn with thread now, part of my 2012 resolution. I will let you know if I think there is a difference to me and my 2 year old Viking Sapphire and my 10 year old Janome 10000.