A word with several meanings, the term can pertain to a ceramic or vitreous porcelain glaze that can be applied to a surface as a pottery or metal finish and then fused to that surface in a kiln. The result is usually smooth and lustrous. Enamel is also a fluid paint that either air dries or is baked to a hard, glossy finish. Source: Ralph Mayer, "A Dictionary of Art Terms and Techniques"