GUTERMANN-Serger Thread. Gutermann’s Premium Serger Thread is 100% Polyester. It comes on Mini King spools that are ideal for overlock and serger sewing. These threads are great for problem-free and uninterrupted sewing on 3 and 4 thread overlock machines as well as standard sewing machines. This package contains one 1094yd/1000m spools. Available in a variety of colors: each sold separately. Imported.