I never thought it was wrapped with "silk", just that it had a smoother finished compare to the limited threads available in the 90s. I have used it with my Bernina since that is what the dealership advised me at the time I purchase my Bernina. I have owned it for over 20 years and never had a thread problem ever.
I have seen polyester thread cut thru quilts made with cotton before the 80s. I have seen polyester batting migrate thru pressed open seams (I used white polyester: came thru my pressed open seams using solid back fabric YIKES!). Maybe I have been an active quilter longer than you have. Back in the days when I learned to quilt, there was no internet, no u-tube, no W&N, no Hobbs 80/20 batting, no acrylic rulers. Those were very dark days because we only had check gingham and calicos to use in our quilts. But that was an improvement over feed sacks (that WAS before my time).
But with the improvements over the decades, things have changed for the better. Invisible thread no longer feels like fishing line. These are Facts, not myths. They are history in the evolution of quilting. We are so lucky to have all the equipment, fabrics and patterns now a days. My Great Aunt Maude made her quilts with a treadle, pencil and scissors. I am thankful every day for my rotary cutter mat and rulers!
