When I first started quilting I used cones given to me by my SIL who worked in the local Laura Ashley factory. I had loads of trouble with them - breaking, & masses of lint so they were relegated to basting thread and I gave away alot of them for that purpose. I then bought new serger thread and that was much better and I carried on using that for years. However a couple of years ago 3 of my first quilts have been returned for repair and all the seams were coming apart.(They would be about 15yrs old) I just put them on a another backing and free machined them. Anyway my point is that since then I haven't used serger thread or polyester cos that melts as I like using very hot iron and my favourite is masterpiece from superior threads with bottomline in the bobbin.