esmaltes

Esmaltes are vitreous coatings applied to substrates such as metal, ceramic, or glass and fused by high-temperature firing to form a hard, glassy surface. They provide protection against corrosion and wear and offer decorative color and gloss. Enameling differs from conventional paints in that the coating becomes a continuous glass phase bonded to the substrate.

Composition and forms: Enamels consist of a glassy matrix, fluxes, and colorants. They may be frit-based (ground glass powders suspended in a vehicle) or ready-to-use suspensions. Pigments and opacifiers yield a wide color range; opacifiers like titanium dioxide create opacity, while transparent enamels rely on the base glass. The chosen combination must match the substrate’s thermal expansion to avoid cracking (craze).

Application and firing: Substrates are cleaned and sometimes primed. Enamel is applied by dipping, spraying, or brushing, then fired in a kiln or furnace at temperatures typically around 700–900°C depending on the formulation. The firing fuses the enamel into a durable, smooth surface; multiple coats or underglazes can be used for effects.

Uses and history: Enameling has ancient origins in the Near East and Asia. It is used on pottery and porcelain, metal cookware and appliances, architectural metalwork, and art pieces. Modern enamels emphasize lead-free formulations and compliance with safety standards; some uses require specific thicknesses and bake cycles.

Notes: In Spanish and Portuguese, esmalte (esmaltes) can refer to enamel coatings as well as nail polish; context clarifies meaning.