1.0mm Ritza waxed polyester thread also know as "tiger" thread. The thread is finely braided, flattened and is extremely strong. It comes lightly waxed to hold its place and will not gum up your projects like many other waxed threads! Polyester thread is preferred for sewing almost anything that requires strength and durability. It performs well with all types of leather and sewing projects. It is strong, has excellent sunlight (UV) resistance and will keep you projects lasting for a very long time. This is one of our favorite threads because of its rich colors, quality of braid and the way it lays down in your leather.