Nylon TMDT (also known as Nylon 6-3-T) is a type of transparent nylon, useful where transparency and chemical resistance are required in the same application. This polymer was launched by Dynamit Nobel in 1968 under the name Trogamid T.^[1] In 1988, the business was acquired by Hüls which later became Evonik.

TMD is derived from isophorone, a trimer of acetone. The polymerization is unusual for a nylon polymer. In the first step TMD is reacted with dimethyl terephthalate and methanol is removed to form an amide. In a second step polycondensation is done to make nylon TMDT.^[2]