Rheingold Polyester No. 40 Baby Blue, Commercial Polyester Cone, 5500yd/5000 m. Rheingold is a brilliant all-purpose machine embroidery thread made from the highest-quality trilobal polyester. Unique new manufacturing processes produce a thread of outstanding quality, combining a silky sheen and ease of use with excellent stitching characteristics and a color fastness to high washing temperatures. Rheingold Polyester is unaffected by chlorine bleaches and stands up the roughest of wear so it is the ideal embroidery thread for clothing which has a lot of use - for example, sports, childrens and workwear.