The Craft Guild of Dallas typically hosts 2 visiting artist workshops annually in the clay department. This year the first visiting artist workshop featured porcelain slab building with Margaret Bohls, who teaches at the University of Nebraska Lincoln alongside Eddie Dominguez and Pete Pinnell. I have been darting a lot of my thrown pots and trying to troubleshoot hand-building for such forms as oblong butter dishes and irregular shaped trays so I jumped at the chance to learn some practical techniques regarding how to execute said forms.
Some of Margaret’s paper templates.
To regularize her forms and maintain clean, straight seam-lines Margaret employs the use of paper templates based on squares or cylinders. Shown above are mostly bowl patterns. These are square-based with curved edges, and she usually drapes them over round slumps then adds a folded-over slab rim and flattened jelly roll for the foot ring.
2 days worth of demo pots.
Everything you see above was created with darted slabs, except for the vase which utilizes leather hard slabs joined together. The pitcher spout has a squared off v-shape template, while the teapot spout template resembles a whale tale, as Margaret pointed out. The handles are created by rolling slabs up like a jelly roll, then slapping them on a work surface that is slightly moistened to flatten to the desired handle shape. Note: flatten with the seam-line up or you’ll smoosh the seam out of existence! They are surprisingly beautiful whether as a lug handle on a tray or more stretched out on a taller form. The back center bowl features the jelly roll handle as a foot ring, instead. Margaret credits Lana Wilson with showing her the jelly roll handle technique originally.
For darted slab pots all edge and lip treatments must be done on the flat slab before assembly when it’s about 1/2-way between freshly rolled out and leather hard. Be careful to rib both sides of the slab often during working them and you may wish to stretch and thin the slab prior to cutting out the template. Shape the lip before cutting out the darts or cracks will form in the corners as you manipulate it. Seams are created by overlapping the edges so thin and smooth the edges of the darts accordingly. Scoring and slipping is recommended, followed by carefully pressing the seams together until well-stuck without running your finger over the edges themselves. You can go back in with a sponge and fingernail combo to clean up the seam when it’s closer to leather hard, so don’t worry about little imperfections or you might overwork or damage the edge. Margaret typically cuts out the base after the walls are assembled by simply tracing around the base of the pot on a slab, then carefully pressing the edges up onto the wall with long, smoothing thumb strokes.
Working with a textured slab to create what Margaret calls bumpy ware.
To create the grid pattern, Margaret carves plaster them presses freshly rolled out slabs into the texture, being careful to smooth the backside to compress it and minimize cracking. She then lays it face-down on foam to raise the areas between grid lines, and as you can see doesn’t touch areas that get cut out as darts. After darting and assembling all pieces, plus adding pulled handles for decoration and feet, rims, coils, and sprig molds, this form becomes something like this:
A bumpy ware vase from the artist’s website.
The lattice base is usually constructed with earthenware. She also fires the vase on wasters so the feet don’t get caught on the kiln shelf as the vessel shrinks, which would warp the whole form.
My trial pots from the 1st day, re-using the same template for all 3.
I churned out three pieces between demos on the first day, from a paper template I generate with three darts instead of four. One of the darts is tied into the full length seam-line as well. Due to uneven drying rates in the clay lab, two of these cracked insanely but here they are for posterity. I like the process and for some reason I’m able to really cover some ground working with slabs. Other than the fact that porcelain is really finicky about cracking and the method creates a lot of waste I really enjoyed the process.
A bottle vase with handle. Despite being covered with a small piece of additional plastic around the handle, a massive crack rendered it unsalvageable.
On the second day I made an oblong rounded rectangular tray with surface texture and handles on each end. It cracked also, but I patched it and wrapped it carefully so we’ll see what happens. At least I can snap a reference photo before destruction if it fails. I also constructed a medium-sized square bowl with an added jelly roll foot ring. So far no issues with that one.
My demo pots from the third and final day.
On the third day she demonstrated the foam texture method so I constructed this tall canister jar. I also hammered out a giant butter dish with a press mold of my own design, both textures based on a Japanese kimono textile pattern. The lid flange for the jar is on the bottom part, which according to Margaret helps keep the walls from warping since the top of the lid usually keeps that part from shifting.
Butter dish aerial view.
Although I was tempted to trace Margaret’s templates, all of my pots came from paper pieces I cut myself based on her techniques. I used bisque and leather tooling stamps to create most of the textures other than those on the walls of the jar.
I added three of her gorgeous black slab-built pots to my collection.
At lunch on the first day of the workshop demo participants pulled numbers and selected pots via lottery. I went more overboard than usual with this haul, but each piece spoke to me and I love the sumptuous black glaze. I can’t believe it’s not reduction! (pun intended) But yes, these are fired in oxidation. I already acquired one of her square slab-built dinner plates from AoTP last year, also.
Here’s another view of the pitcher, yum!
I thoroughly enjoyed the workshop and learned a ton of new techniques to bring into my home studio. Thanks, Margaret Bohls!
