Polyester thread provides the right amount of stretch for maximum performance. 10 multi-color spools of 100% Polyester thread at 200 yards each. 2 White 2 Black 1 Light Blue 1 Gray 1 Red 1 Navy 1 Brown 1 Ivory The sewing result is a smooth top side and a smooth underside. The color variations give you what you need for most of your projects and also makes it convenient to have what you need when and where you need it.