Original insulation trade vintage catalog for STAR PORCELAIN COMPANY, was located at 61 Muirhead Avenue, Trenton, NJ. Frenchtown Porcelain Company. Manufacturers of Frenchtown spark plug insulators, Thermolain, Vitrolain, Humidolain, Nu-black and lavolain. Disbound from a large 1948 electrical construction materials book, this unique old one page technical brochure would display wonderfully matted and framed. A marvelous addition to your retro electrical equipment library.