I prefer using a polyester thread to quilt with. I quilt with a longarm machine so need the extra strength from the polyester threads to reduce breakage. I also found that the 100% cotton threads not only produced more lint, but they tend to break after the quilt was off the machine and being used, especially if the quilting was stitched diagonally. i do want my quilts to be used for a long time and be able to stand up to that use.