Phases are specific forms of materials. The most familiar phases are solid, liquid and vapor. Any phase of a material is identical in composition and structure in all parts of that phase. For instance, a glass of water is the liquid phase of H2O, top to bottom; if it weren’t, we’d call it something else, like ice if it were solid (structural change), or lemonade if it had lemon and sugar dissolved in it (compositional change).
Remember, in high school chemistry class when you found yourself thinking, “when will I ever use this stuff in my life?” (unless, of course, you always dreamed of becoming a chemist). Well, once you have become hooked on pottery and ceramics, you will probably find yourself delving into glaze chemistry. Learning how different materials contribute to glazes and clay bodies is very important in expanding your abilities as a ceramic artist. So here we’ve gathered a bunch of articles and information on glaze chemistry to help you understand this incredibly complex and fascinating subject. 33 Tried and True Glaze Recipes, a perfect resource for potters and ceramic artists who are ready to experiment with custom glazes, or for those who have grown tired of their own tried and true glazes.
Beautiful, soft, muted-color brushstrokes and washes of water-soluble metal salts decorate Gary Holt’s translucent porcelain bowls and plates. The simplicity and quiet presence of his works belie the years that Holt spent experimenting and perfecting his technique. Using water-soluble metals salts (WSMS) demands excellent technical skills and careful attention to details.
Barium carbonate has long been used as an ingredient in high-fire glazes, sometimes conferring unique properties upon glazes. One of the alkaline earth carbonates, it has also been used as rat poison (large doses can be toxic to humans as well). Glazes containing it ought to be checked for barium leaching if they are intended to hold food or drink, or reserved for surfaces that do not come into contact with food. It is not my intent to present the research on barium toxicity here, but to present a course of action for replacing it in glazes.
One of the more fascinating, sometimes frustrating parts of ceramics is learning to balance the innumerable factors that affect the outcome of a firing. Glaze ingredients, the clay body used, firing cycles, atmospheres, kiln-stacking techniques and geography (to name a few variables) can all affect firing results.
How many times have you copied a glaze formula, only to find that it didn’t work as expected? It is not unheard of for glazes with the same formula to produce different results. While this may seem like a dead end, it does not have to be.
Imagine a ceramic glaze that fires perfectly at both cone 10 and cone 6, in reduction and oxidation, and in a soda firing, yet still produces a variety of exciting, stable colors. Kristina Bogdanov, who teaches ceramics at Ohio Wesleyan College in Delaware, Ohio, was intrigued by the possibilities when she realized that one of… Read More »
Detail of a plate glazed with Sumi’s Volumetric Clear Glaze mixed with commercial stain. Mixing ceramic glazes from scratch can be intimidating to those just getting started. And sometimes it just isn’t practical or possible to purchase or have access to an accurate gram scale. But that doesn’t necessarily mean that mixing glazes is out… Read More »
On Monday, we presented a couple of ways that you can expand your glaze palette without purchasing new materials or experimenting with new glaze recipes. If you missed that tip, you can see it in the online archives (along with every other feature we’ve published—just click on “Features Archive”). As promised, today, Lou Roess shares… Read More »
If you’d like a bigger selection of glaze colors, but don’t have the time or money it takes to mix and test new ones, don’t fret. Working with what you have on hand can yield some interesting results. Today, we’ll show you a couple of simple ways to get more from your studio glazes. Whether… Read More »