seldom found all original early 20th century deep cobalt blue porcelain or vitreous enameled "keep this place clean" informational sign designed and fabricated by the baltimore enamel & novelty co., baltimore, md. this early single-sided sign contains the rich and dark blue porcelain with sunken lettering. the four corners contain minor loss of porcelain and the grommets (if they were there to begin with) are long gone. the sign is comprised of heavy gauge rolled sheet iron with multiple coats of vitreous (fired powdered glass fused to a substrate or surface) enamel. the diminutive sign was salvaged from an upstate new york factory.