There are many methods of appying enamel to metal. Each technique has it's own unique characteristics.
CHAMPLEVE : A term for cutting the metal with engraving tools (or etching the metal surface) to make recesses for the enamel to be placed.
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BASSE TAILLE : This is a development of the champleve method whereby the surface is engraved with a pattern that shows through a transparent enamel.
CLOISONNE : A technnique that uses fine wires to make partitioned areas for the enamel colours.
PLIQUE A JOUR : Commonly known as the stain glass window effect. The design is pierced out of the metal with a saw, making a framework for the enamel. Transparent enamel is used so that you can see through the shapes.
PAINTED ENAMEL : Very finely ground and highly pigmented enamel is painted with fine brushes onto a base layer. Over many firings, detailed realistic effects can be achieved. Traditionally used for figurative work.
SCRAFFITO : Working with enamel as dry powder or with liquid, marks are scribed into a layer, fired, and then applied with subsiquent layers of enamel to create marks, images and patterns.
STENCILLED : Enamel is sifted dry through a pre cut shape to form a design.
PRINTED TECHNIQUES : Screen printing dry powdered enamels/or enamel ink/or painted enamel, plus applying images via rubber stamps are methods that can be used over a fired enamel base. Printed decals can also be fused into the enamel surface.
SIFTED TECHNIQUES : Many alternative effects can be achieved via sifting. Sifts are graded to grain sizes, which enables a range of effects.
LIQUID ENAMEL : Enamel suspended in a slip like consistency. Liquid enamels are dipped, poured, painted or more efficiently sprayed onto the metal surface before firing. It was originally an industrial technique but is now a popular choice for modern enamelists.
Images from ENAMELLING published by A&C Black 2006