I buy all my quilting threads online, mostly from Connecting Threads, both their cottons and polyesters. Also love Aurifil when I can find it on sale as all my quilts are given as gifts so have to save where I can. Superior offers a variation of threads. Find what your machine likes and go from there. I do have Superior's and Aurifil's thread charts as well as my embroidery threads' charts to give me a better view of the actual threads. I also use embroidery threads on my quilting machine at times. If I find a thread my machine doesn't care for then I'll use it up in piecing on my domestic machine. Hate to waste it.