Need more feedback than my own. I have always done my fmq with cotton thread and used whatever brand I happened to find in color I wanted. This week I quilted one using Isacord polyester. I purchased $300 starter pack last year when I was thinking of using embroidery machine. Sold machine so thought I'd use thread for fmq as colors were so pretty. A friend who teaches told me this week that you can never fmq with polyester as we have no way on knowing how well it will hold up in your quilt in a hundred years. Anyone else use polyester? Do I really care if 100 years from now the thread breaks?