Faceted Forms, Geometric Glazing

Integrating Form and Surface

In all of my ceramic work, including glazed stoneware bowls with faceted planes and cut feet, I seek to integrate form with surface design and glaze color. The form of a bowl and the cut foot guide and inform my choices of glaze placement and design—and what I envision for later glaze treatment determines the bowl’s form, too. My process is one of continual interaction between the technical steps of making a pot, particularly throwing, altering, and glazing.

The bowls shown here are from a series of pots that I have investigated for a number of years. This series began with ideas for squared or rectangular pots and, over time, I developed a process to suit my inclinations and design ideas. As one who loves throwing, it’s natural for me to use the wheel to create the basic forms. In the wet state, even while still on the wheel, the thrown form can be altered and sculpted toward its finished shape. The various drying stages of clay have unique working qualities and using these drying properties to the best advantage seems like the logical way to sculpt crisp, hard-edged, and faceted forms. As I make decisions on glaze shape and placement, an important consideration is finding the right scale relationship between the glaze elements and the form. Again, I hope to integrate form with surface design, texture, and color.

1 Cross section of freshly thrown bowl. Note thickness in the foot and lip.

2 Measuring placement of the 6 facets using a dividing disk as a template.

Driven by various art influences (20th-century ceramics and abstract painting, quilts, Southwest Native American pottery and textiles) and by visual and travel experiences, my work begins through drawing. Working sketches are an efficient and enlightening way to develop ideas and to generate new approaches. Through drawing, I can discover many variations for pottery forms, like bowls, and sort through possible ideas to determine what seems worth pursuing in clay. I begin a series of pots by selecting a group of sketchbook ideas that seems most interesting to me at that moment.

A focus of my drawing is glaze design—types of geometric shapes, their placement, direction, size and color—always in relation to particular form ideas. As I make a bowl series, initial ideas about glaze design evolve further through continued drawing. This is vital since the glaze design often dictates how a bowl’s feet will be cut and the sides faceted. The form of a bowl is partially determined by its glaze design, but since the bowl form is made before the glazes are applied, working drawings are important to have before I even throw the initial forms on the wheel!

Forming

The scale is determined by what might work best for the intent of the bowl. Once the scale is established, the clay is weighed and wedged. Consideration is given to the size of bowl and to the extra height needed to accommodate creating the cut feet.

To make the bowl, center and open the clay in the typical manner, but leave extra thickness at the bottom when creating the floor. (This extra thickness in the bottom determines the final height of the cut feet.) When the walls are pulled up, a bit of extra thickness is also left at the lip and in the lower wall and base. A sweeping interior curve with no interruption or steps is best. Articulate a strong lip (1).

3 Define the facets by pushing out evenly from the bottom to the top at the marks.

4 Bowl with 6 facets defined in soft clay. At the leather-hard stage, paddle the facets.

I mark a predetermined number of facets on the clay wall using a sectional guide or dividing disk (2). At each mark, I run a finger from the base of the freshly thrown bowl to the rim and push out from the inside. This gradually indents a line at each mark that divides the facets (3). Care is taken not to mark or distort the lip. Allow the pot to stiffen up. Then, at the leather-hard stage, I often paddle the facets for more definition (4).

After flipping the bowl over onto its rim and centering it on the wheel, the outer planes are roughed in (5) and a round foot is trimmed into the bottom center of the bowl (6). A 45°-angled bevel is cut in the interior wall of the foot. This detail will be mirrored on the outside of the trimmed foot later. Then the entire foot is smoothed with a rubber rib.

5 Trim the outer foot area to match the facets defined earlier.

6 Trim the inside foot ring, leaving extra thickness for free-hand trimming.

7 Use a Surform rasp to define the facets to about ¾ down the bowl wall.

8 Smooth and burnish the facets using various rubber Mudtool ribs.

The bowl is now ready for rasping using a Surform blade to define the facets and clarify their edges. Rasping begins with the top wall and lip (7). After each facet is defined, remove the rasp texture by scraping and smoothing first with a metal rib, then with a rubber rib (8), taking care to keep the edges between the facets well defined. The smooth surface helps clarify and facilitate the eventual glaze design.

After flipping the bowl over onto a thin piece of packing foam to protect the finished leather-hard lip, begin rasping the lower half of the bowl to define the facets to the foot. These facets meet at the foot (9), while the interior of the foot remains round. The outer edge of the foot is cut with 45°-angled planes, mirroring the interior foot detail (10). This angled plane helps to define the foot and create a clear conclusion for later glazing. As with the rim, remove the rasp texture using metal and rubber ribs.

The foot layout is now measured and marked. Using a fettling knife or an X-Acto blade, carefully cut wedges in the foot (11), paying attention to the depth of these cuts to avoid cutting through the wall. Once cut, the notches are refined to correspond to the other details of the foot (12), and the bowl is left to dry. When bone dry, the edges of the feet are slightly smoothed with a finger, then the bowl is slowly bisque fired.

9 Rasp the foot, taking care not to trim the wall of the bowl too thin.

10 Create a 45°-angled bevel at the base of the wall, mirroring the inside of the foot.

11 Measure cuts in the foot, then cut them out using a sharp knife.

12 This is a view of the wedge-shaped, cut foot completed in the leather-hard stage.

Glazing

The surface design begins at the foot. Seemingly infinite design variations can spring from the cut foot. I roughly draw the design on the bisque ware with a #2 pencil (the marks will burn off in the firing), then block out the design using tape. I brush on wax resist to preserve areas that will remain unglazed. Next, sections for different glazes are brushed with latex rubber resist. All are allowed to dry. The interior is glazed, and then a series of colored glazes are applied to the exterior of the bowl.

This is a progressive process of glazing. It involves applying one glaze via dipping, waxing over that glaze, then removing latex from another section, and applying glaze to that section. I apply successive glazes in this manner to complete the design.

Firing

I salt fire my work to cone 10, taking care with the placement of the bowls in the kiln. If the pieces are exposed to too much salt, the edges in the glaze design will run due to the excess flux, and if they are exposed to too little, the glazes will appear flat. The best firings balance these effects, enhancing and unifying the form and surface of the bowl.

David Crane is an emeritus professor of ceramics at Virginia Tech in Blacksburg, Virginia. His ceramic works have appeared in over 300 national and international exhibitions, and he has lectured and demonstrated widely. His work appears in private, university, and museum collections. To see more of his work and learn more about his career, visit www.davidcraneceramics.com.

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