West German Lava and Volcanic Glazes

An Introduction to West German Lava and Volcanic Glazes by Forrest D. Poston

Ever since the term fat lava became popular, it’s misuse has increased, so it’s probably time to talk about some of the glazes so people can distinguish between them and use descriptive terms with a bit more precision. While most of the West German pottery glazes and decorations fit into the simple terms of glossy, matt, or semi-matte, there are variations that fall into the sometimes overlapping categories of drip, lava, and volcanic, and these are the terms I’ll talk about for now.

I’m not a trained potter, so my technical knowledge is somewhat limited. Keep in mind that I’m not trying to explain these glazes for potters but for collectors, which means some of my terms may not be used as precisely as they should, and they should not be applied outside of the realm of West German pottery. Of course, I’m also open to input from people who do have the technical knowledge I lack.

Also, the terms lava and volcanic are used here as descriptive terms and should not be confused with pottery that's advertised as lava or volcanic because materials used came from volcanic sources.

Drip Glazes

Defining a drip glaze is fairly simple. One glaze drips/runs over another. This is usually done in strongly contrasting colors but can also be done with color variations almost too subtle to see. Most drip glazes are a glossy glaze over a matt or semi-matt glaze, but there are glossy over glossy glazes. Drip glazes were quite popular during the Arts & Crafts era and into the 1930’s. The best known work in American pottery is by Fulper, but Belgian and French companies did excellent drip glazes during the same period.

Lava Glazes

To begin, the term Fat Lava is probably a mis-translation that came about when German sellers meant to describe the thickness of the glaze. In other words, fat lava is often a drip glaze with the top glaze significantly thicker than the underglaze. In these cases, it can simply be the flowing quality of the top glaze that earns the name “lava” regardless of the texture.

However, in some cases the top glaze is controlled to avoid such flow but may have a lava-like texture. This may consist of cratered surface or simply a thick, globular glaze. Some glazes have a crystalline-like appearance that look rather icy but still deserve the lava name because of the thickness and flow.

While a lava glaze most often appears around the top portion of a vase, it can be found on any part or even over the entire vase.

Volcanic Glazes

To add to potential confusion, there are also volcanic glazes, but volcanic and lava are not necessarily the same. A volcanic glaze gets its name from craters or pops in the surface of the glaze. The best known volcanic glaze artist is Otto Natzler, who was born in Austria in 1908 but came to the U.S. with his wife Gertrud (the clay expert of the pair) in 1938. Many studio potters have since worked with volcanic glazes but no studio or company produced the variety or quantity that came from W. Germany from around 1965 through the 70’s.

Volcanic glazes can be categorized based on the surface textures. Those that most clearly deserve the name have numerous rough-edged craters. Craters can be fairly large or quite small. The smaller version is what I call a pumice glaze.

Another variation has smooth-edged craters rather than rough. I’m not sure if the technique was a variant of the traditional volcanic glaze with additional firing to soften the edges, or if it’s a significantly different technique.

Condition Considerations

Given the thickness, lava and volcanic glazes often have bubble pops (other than those intentional caused in a volcanic glaze). While such pops are considered a defect on traditional glazes, on a lava glaze they should simply be considered a natural part of the territory, an additional variation on the texture.