I have been using Coats & Clark for many many quilts with no issues. Took my 1996 Viking Rose in for service last year and he found no problems other than I wore down the screw that the Walking Foot arm attaches to. Of course, I don't know about the quality of the Coats & Clark thread sold now. All my thread is from the 90's. I don't think the quality of anything is as good as it used to be.