In the Studio: Commercial Glaze Tips and Tricks Deanna Ranlett

Appears in the Sep/Oct 2019 issue of Pottery Making Illustrated.

Low-fire commercial glazes can be successfully layered to build effects and change the appearance of the individual glazes. Many low-fire glazes, like Mayco’s Foundations line, were made to self-level. This creates a fantastic base for layering more colors or trying streaking effects, paper resist, screen printing, and more. Solid, glossy colors can be layered with matte or crystal glazes to create new effects. Low-fire glazes can also be layered on top of underglazes. Resisting glazes with paper or fabric can be a fun way to build visual texture in your work.

Tip 1: Fabric and Paper Resist

Glaze with two coats of any low-fire glaze—in this project I’m using the LG and F-series from Amaco and Foundations from Mayco, but you can use any low-fire glaze that has the characteristics you want. Solid colors work best for this technique because you’re relying on contrast to show the fabric elements you want to capture. Paint a base layer of glaze onto your plate. Once tacky, pat your fabric (lace, tulle, or any decorative fabric with an open weave) into the damp glaze (1), and apply one more coat of your base glaze to hold the fabric down during the next glaze application.

Let the glaze dry fully and apply one coat of an underglaze on top (2). Before it’s dry, pull the fabric away to reveal your pattern (3). Underglazes dry like cement, so if you wait too long, you won’t be able to remove the fabric. You can do this last step with glazes as well, but know that matte glazes and ones that don’t move very much work best for this technique. Allow the underglaze to dry, coat the plate with clear glaze, then fire to temperature (4).

Tip 2: Layering with Crystals

Finding unique glaze surfaces can be challenging, but when working with commercial glazes, the world is your oyster. When layering glazes, it’s essential to test. I tend to build combinations that start with applying the most opaque glaze first and then adding modifier glazes like translucent, feathery,  floating, or crystal glazes on top. This typically yields the most successful surfaces in terms of interesting interactions.

To develop a crystal surface on a jar, wipe the bisque-fired surface with a wet sponge to remove any dust that may interfere with glazing. Using Coyote’s MBG164 Crystal Nebula, pour a decent amount of glaze into the body of the jar and swirl it around up to the underside of the lid gallery. Pour the excess glaze back into the bottle. If the glaze is thick, thin it with a small amount of water to ensure an even coat. Do the same for the inside of the lid. Clean up any drips on the outside of the jar or lid. Be sure to remove all glaze on the inside of the lid gallery that may cause the lid to stick after firing.

Let the glaze dry fully for about 30 minutes to an hour. Next, I’m using Coyote’s MBG034 Archie’s Base to glaze the exterior surface on the jar and the lid. Brush a thin, even layer onto the entire exterior using a soft fan brush (5). Let this layer dry for a few minutes then apply another thin layer.

Let the glaze dry for about 20 minutes, then apply Mayco’s SW150 Celadon Bloom. Apply a thin coat to the top of the lid and finial. Adding too much glaze may cause the glaze to fill in some of the gaps in the finial curl.

Celadon Bloom has little crystal chunks that melt during the firing and cause a special effect in the glaze (see 6). When you shake up the jar, some of the smaller, lighter crystals may distribute and be applied to the piece while brushing on the glaze. However most of the larger, heavier crystals may sink back to the bottom. Apply these crystals with a fine-tipped brush in specific areas (6). Use a spoon to scoop out some of the chunky crystals at the bottom of the jar. Gather a chunk or two onto your brush, and randomly distribute them onto the surface of the jar. Try to place them over the surface glazed with a coat of Celadon Bloom.

Placing the crystals too low on the exterior may cause the crystal to drip past the foot. If you’re having trouble sticking the crystals on, first apply a small dot of wet glaze on the area you want to put the crystal. Do the same with the lid.

Coyote’s Crystal Nebula and Archie’s Base are both crystalline glazes that do well with a slow cool. Fire to cone 6 and cool slowly or program a ramp to downfire to help form beautiful crystals (7).

Deanna Ranlett has been working with clay and glazes for 18 years and is the author of the new book Off the Shelf, Outside the Box: A Guide to Experimenting with Clays, Glazes, & Underglazes, available at https://mycan.ceramicartsnetwork.org/s/shop.