SD stands for single dyed. This terry cloth has been dyed once. As a result, the terry cloth is not completely colored. This ensures that you also see white hairs in the terry cloth. Furthermore, the quality is the same as our standard terry cloth. This terry cloth is made of 90% cotton and 10% polyester. The terry cloth is double looped so that it feels very soft on both sides. Terry cloth is used, among other things, for bath towels, washcloths, bathrobes and changing mats for babies.