I purchased this Tire 50wt silk thread from Superior Threads. It a beautiful shiny thread and is heavier than the YLI Silk which is a 100 wt. 
I used a 14 quilting needle, Bernina BSR with stitch length 2.0 and the default tension of 4.0. I don’t know what brand of batting is in this sample but again think it is some sort of cotton.I love this thread, the shine in incredible and it paired up nicely with the Bottom Line thread from Superior Threads that I used in the bobbin. The backtracking shows but doesn’t overpower the other stitching. You do get a heavier line of quilting than with the 100 wt. silk threads so this would not blend into the background as easily as the lighter weight ones – if that is what you want. It is a filament silk so is many long strands of silk fibers wound together. No lint left in the machine from this thread.
I would definitely use this thread again but will consider the cost and how large the project is to be quilted. Each of these 109 yard spools is $5.99 so the thread cost could be pretty high if you were quilting a large project. You might want to try one of the trilobal threads to get the very shiny look of silk but pay a lower cost per yard of thread.
Lynn
