Super Helpful Tips (and a Couple Recipes) for Layering Glazes Gabriel Kline

I admit that glazing has historically been my least favorite part of the ceramic process. This year, however, I made it a special point to devote more time to experimenting with new recipes and improving my glazing results. One way to discover new, exciting glaze surfaces is to allow yourself some time to experiment with layering them. 

18,515 Layers

Layering glazes is a passion! If you engage in careful glaze preparation, skillful application, and detailed note taking, you can create a nearly infinite variety of combinations. If you stocked only five glazes, you could layer them in 18,515 different ways! It should be noted, however, that color combinations do not work according to the traditional color wheel (e.g., red plus blue does not necessarily make purple). Additionally, the combinations of ingredients in the different glazes may intermingle in interesting ways. For example, a combination of two matte glazes can run down the side of a pot. For this reason, always use a cookie and/or wadding underneath any new (or known runny) combinations to minimize the need for grinding and potential damage to kiln shelves.

When layering glazes, first apply a base coat through dipping, pouring, brushing, or spraying. Allow it to dry to the touch before adding a second layer. The second and subsequent layers of glaze should be applied slightly thinner, either by using a shorter count or by decreasing the specific gravity. I have found that it’s best to wait 2 to 3 hours before applying a third or fourth coat—sometimes even overnight. To play it safe on new combinations, aim for the second glaze to go no lower than a third of the way down the pot and for the third coat to go no more than a quarter of the way down the pot. Once the degree of melt can be observed, you can adjust for the next firing. 

When working with layering glazes, you may find that some glazes layer poorly, flaking off the glaze below it. A possible cause is a difference in clay content in the glazes. When a glaze with a high clay content is applied over a glaze with a lower one, the glaze with more clay can tend to flake off when it shrinks. Reversing the order of application can solve the problem, but it will give a different look to the layering. Alternatively, you can try adding 1% CMC gum or 2% bentonite clay to the low-clay content glaze. A glaze that has sat unused for some time and had a chance to flocculate may also tend to flake. If so, you could add one drop of the deflocculant Darvan 811 per cup and mix until the glaze noticeably thins.

Two-Glaze Combinations

Here’s where the fun begins! To get your bearings with any new set of glazes, you first want to test each glaze in combination with every other recipe in the set. For each glaze, I dipped ten of the tiles for a two-second count in the same glaze. I then inverted the piece and dipped the top one-quarter of the tile in a different glaze. With eleven base glazes, I ran a total of 110 two-glaze combination tests to see how each glaze operated with every other glaze in the group.

The results of the two-glaze combinations tests were, as one should expect, not all spectacular. In fact, some of the tests were downright ugly by anyone’s standards! But this is important information. Knowing which combinations do not reflect your aesthetic vision can be as important to honing your palette as knowing which ones represent you well.

In any case, these two-glaze combination tests will show you how the glazes perform with each other, including degree of runniness in each combination. You can use this information to make decisions about how much of the first glaze you want to show on the outside of your pot. If a combination doesn’t move that much, you now know that you can dip the second glaze further down the piece to create a different look. Similarly, for the very runny combinations, you now know that you should keep the second glaze toward the top of your pot to allow it to run. 

While many of the best combinations at cone 6 come from three or more glazes (which helps build depth and variation), I discovered several really striking two-glaze combinations. These combinations look great as they are, but also served as the basis for the next set of more complex tests. 

the author Excerpted from Odyssey ClayWorks Director Gabriel Kline’s Amazing Glaze Recipes and Combinations, published by Quarto Press.