- 670 TOPAZ® bathtub walls with embossed tile pattern as manufactured by E.L. Mustee & Sons, Inc. Shall be semi-gloss, three-piece wall. Panels are molded fiberglass using matched metal molds under extreme heat and pressure with a uniform thickness of 125 mils and mount direct-to-stud walls. Includes center panel with molded-in shelf and two side panels. Self-aligning panels using a tongue-and-groove connection. Shall meet ANSI Specification Z 124-2011. Color: White. Install in compliance with local codes.