Some of the main influences in my work are contemporary and historical pots from the following traditions: English slipware, Japanese and Korean folk pottery, and North American Appalachian pottery, along with works made by contemporary Minnesota potters.
These regions, time periods, and approaches to making pottery create the foundation for my work. Nature has a huge influence on me, and I try to capture a sense of movement and energy through my gestural mark making, which is reminiscent of Impressionist paintings, but subtractive instead of additive.
I am drawn to soda and wood firing. I experiment with numerous flashing slips and several commercial clay bodies to slowly develop a vocabulary to achieve surface results and colors that are of interest to me.
Clay and Slips
The commercial clays I use are mainly white, grogless stoneware and porcelain. Experimenting with different clay bodies and slips is where I get to play. My language is centered around form, pattern, color, and surface techniques—using just a few clays in my studio combined with different types of flashing slips. My interest is largely focused on these clay and flashing-slip combinations in relationship with heavy reduction firing to create carbon trapping. This relatively simple and direct approach yields an array of results. Pairing white stoneware with flashing slips allows for a bright and distinctive surface, highlighting the effects of the kiln atmosphere.
I apply the flashing slip when the pots are leather hard. Slipping a pot that has been bisque fired will not work with this technique. The porous bisqueware absorbs water and dries out the slip too quickly, not allowing time to draw through the wet slip.
Once I trim, add handles, and complete pots in the leather-hard stage, I wax the bottoms. The wax protects the foot or the bottom by preventing the freshly applied slip from pooling and absorbing into the pot when it’s placed upright. It also helps prevent the pot from sticking to ware boards and makes it easier to clean slip off of the foot.
The surface decoration is created after the slip has been applied to the pot, but before the slip sets up. Timing is everything. There is a narrow working window before the slip fully sets up during which I can make marks that are smooth and fluid. In the working window, the slip needs to be set up just enough so it won’t run down, distorting the designs. At the same time, the slip needs to be wet enough that I can to draw through it to expose the clay body underneath. In essence, this is a form of the sgraffito technique, using my fingers to draw through the wet slip rather than carving through to the clay body. I have tried other approaches, but enjoy the line quality that my fingers have more than that of a tool. The sensitivity and control of my fingers really allows me to feel the pressure and make specific adjustments to achieve a fluid sense of movement and texture. The exciting action of the decorating process makes it my favorite step.
The process of how each pot will get slipped depends on the form and the size. I dip, pour, and brush the slips on firm-leather-hard pots. If the pot is too soft, the moisture from the slip can soften the pot to the point that it is a challenge to work with. On the opposing side, if the pot is too dry, the slip can slake down the clay when it is applied. Applying the slip when the pot is a bit too dry can also cause it to flake right off of the surface. I have tried to cheat and get away with slipping a pot that I suspected was too dry; it seems fine until after the bisque firing, when the slip shivers right off.
The flashing slips that I use generally work best when applied quite thin. When the slip is the right consistency, I think of it as akin to skim milk. If the slip is too thick, it’s difficult to get a smooth, even coat. On the other hand, if the slip is too watered down, the application tends to be thin and translucent. What I am looking for is a thin, opaque coverage of the slip on the outside of the pot. The thickness or thinness of a flashing slip can have dramatically different results in terms of the fired color and surface. I would recommend testing to see what results you like. Flashing slips, by their nature, flux where wood ash or soda make contact with the piece and are more refractory when not exposed to fluxing agents (like wood ash or soda) in the kiln. Each flashing slip has its own characteristics. For instance, slips that have a lot of glass can be shinier and trap more carbon, while slips that have less glass and more clay tend to have a drier finish to them.
The exterior surfaces of my work have no glaze, only slips, while the interiors have liner glazes. I try to complement the flashing-slip color with the liner-glaze color. My recent go-to liner glazes are celadon and shino glazes.
I fire in several different kilns. My personal kiln is a small propane updraft kiln that is roughly 7 cubic feet in size. One of the colleges where I teach recently converted an old Alpine updraft kiln into a soda kiln, which has been great to fire. I also wood fire with a community here in the San Francisco Bay Area in California. I am going for carbon trapping and dynamic, dramatic flashing results on the surfaces.
The flashing-slip results can vary, depending on how you fire and, as noted above, the thickness or thinness of the slip. I start introducing soda at cone 9. I spray sodium carbonate (soda ash) dissolved in hot water into the kiln. I have been using the ratio of 1½ pounds of soda ash to ¾ of a gallon of hot water. I have found that if I increase the soda-ash content, it does not fully dissolve in the water.
I start by putting the kiln in reduction and adding some small pieces of wood into the burner chambers. Then I begin spraying soda in all the ports of the kiln. Having the kiln in a reduced atmosphere is important during this time (to promote specific colors or carbon trapping effects). The wood also creates carbon in the kiln and helps to create carbon trapping. Once I have sprayed soda in all of the ports, I’ll leave the kiln in reduction and come back in 15–30 minutes to begin the entire process again, until all the soda has been introduced. In my personal little kiln, I add 3 pounds of soda while in my school’s larger 20-cubic-foot kiln, I have been adding 6 pounds of soda. I like to spray rounds of soda to slowly build up layers of glass and carbon on the surfaces of the pots. From my experience, introducing soda in waves rather than spraying it all at once delivers different results.
Every kiln is different, and everyone’s taste is different, so experimentation is key. This is what I do to get my desired results with the kiln designs I fire in. It’s about figuring out how to get the results that you want with the kiln you have. Play with how you fire, how you introduce soda and adjust the two to get what you like. That’s the game. There is no perfect strategy; it’s all figured out on a case-by-case basis with each kiln, clay body, slip, soda application, and the desired aesthetic, so enjoy!
the author Ian Bassett lives and works in the San Francisco Bay Area. He is adjunct faculty at Los Medanos College and a lecturer at Sonoma State College. More information can be found at ianbassett.com or at @craftrider on Instagram.