original c. 1912-20 american antique american industrial black and yellow painted mahogany wood pattern used in the manufacture of a no. 4 "non-clog strainer" connector for stream traps. patterns are wooden forms made to the exact specifications from which a mold is created from for casting metal into. certain colors were used to signify certain specifications for casting purposes. yellow for example, identified areas of hollowness and were sometimes referred to as "core boxes." the unique american industrial pattern was manufactured for the boylston steam specialties co., chicago, il. hundreds of unique patterns are currently being salvaged from the boylston factory. pattern identification in the form of embossed lettering. surface wear consistent with age. two nearly identical patterns available.