Antique Porcelain Knobs add informal style to cabinetry and furniture. Historically these white porcelain knobs are used on dry sinks, pie safes, boxes and country cupboards. White porcelain knobs are made of ceramic with a glossy white glaze. Visual center-screw adds a vintage look. Antique Porcelain Knobs are available in five sizes ranging from ½" to 1-½".