moulding

Moulding, or molding in American English, is a strip of material with a decorative or functional profile that is applied to edges, corners, and transitions in buildings and furniture. It also refers to the process of shaping material to form such profiles, typically by using a mould, form, or cutter. Mouldings define architectural style, hide joints, and provide visual continuity.

Common materials include wood (softwood and hardwood), plaster or gypsum for interior schemes, and modern synthetics such as polyurethane, PVC, and polystyrene. Profiles vary from simple beads and fillets to elaborate cornices, dentils, rosettes, and acanthus motifs. Exterior mouldings often use more durable materials and weather-resistant finishes.

Production methods: wood mouldings are produced by milling or routing from solid stock or finger-jointed assemblies; plaster mouldings are cast onto forms from gypsum plaster; synthetic mouldings are extruded or injection-moulded and finished for installation. In all cases the moulded strips are cut to length and shaped at corners with miter or coped joints.

Applications and usage: interior trim such as baseboards, casings, coving, and chair rails; exterior trim including cornices and window/door casings; in furniture for ornamental edges and frames. Historically, mouldings were central to classical architecture and later adapted for mass production in the 18th–20th centuries, with contemporary practice emphasizing lightweight, cost-effective profiles for drywall and cabinetry.

Installation and finishing: mouldings are fastened with nails or adhesives; joints are filled, sanded, and finished with stain, paint, or veneer. Wood requires sealing to resist moisture; synthetic materials may be painted or left with factory finishes.