A crackle glaze or varnish is a type of finish that produces a crackled appearance. Crackle glazes are popular for antiquing because peeling, cracked paint has an old-fashioned look that complements restored furniture. Crackle glazes can be applied to a variety of surfaces, such as pottery, furniture, picture frames, and even walls. Crackle glazing materials are available at a variety of craft stores, but you can also create the effect with a few items you probably already have on hand.
When creating a crackle glaze, one color is applied as a base coat and allowed to dry before applying a crackling medium. After this medium has dried, a second coat of color is applied, and cracks and peels appear almost instantly. A clear varnish or polyurethane sealer can be used to seal a crackle glaze. This sealer also slows down the cracking process, preventing the second layer of color from flaking away completely.
Many people try to use coordinating colors when applying a crackle glaze because the underlying color shows through. Contrasting colors, such as a dark underlayer and a lighter overlayer, can also look great. If you’re unsure how two colors will look together, test them on a small section of the piece to ensure they’ll look good once they’ve dried. For a more rich look, use a medium like gold, silver, or copper paint on one of the layers.
If you can’t find a crackling medium, you can use white glue instead. White glue acts as a resist layer, preventing the second layer of paint from adhering completely. This will produce a mottled effect; you can also use wax as a crackle finish resist. If you’re working with pottery, use a crack-resistant glaze and follow the manufacturer’s instructions carefully.
The crackle glaze effect is also known as craqueleure, and it is sometimes used to date and establish the provenance of artworks in fine art. A dedicated forger may infuse a craqueleure with dust and particulates from an old piece of art from the right region in case an art inspector decides to chemically analyze the finish. Forgers spend lifetimes mastering the art of a properly cracked final layer of paint in the hopes that their works will pass muster with art inspectors.