At Architectural Depot, we offer both ornate and distinctive mouldings as well as basic mouldings, like this. Flat trim moulding compliments a diverse range of enhancements. Whether you are accenting a wall, door or window, this urethane moulding offers the versatility needed to get the job done. As part of our urethane trim selection, flat moulding is precision molded. Urethane includes a closed cell structure that limits the absorption of moisture. Urethane moulding performs well in exterior applications, because it is non-porous, and able to resist the warping, cracking, peeling and decay that can plague wood mouldings.