These items have beautiful swirls and patterns, from a time when it was thought worthy to devote decorative attention to otherwise mundane objects. Glass door knobs reached their height of popularity in the late 1800's and early 1900's as part of the Art Nouveau period. They were surpassed by ones made of brass, nickel, chrome and bakelite during the subsequent Art Deco era. Nowadays most people are satisfied with cheap pressings.
