A finished, slab-constructed form has distinctive characteristics, the result of a methodical process that moves from concept and scale drawings to the designing of templates and finally the engineering required to bring it all together. Numerous surface treatment techniques, when combined, create visual and tactile depth that add further interest to the work. This process appeals to my problem-solving nature, offering many challenges that keep me engaged.
My work is strongly influenced by the craft traditions of many cultures, particularly those of Japan and Africa. The strength of Mid-century Modern design, with its sleek lines and use of geometry, is also a constant source of inspiration.
To create the pattern for the body of the bottle, which is 15 inches high with a 4-inch-diameter base, fold a 36-inch-long sheet of newsprint or kraft paper in half lengthwise. Attach the pin point of a trammel set to a yardstick at 35 inches, and the pencil point at 1 inch. (Alternatively, use a string with a push pin at one end and a pencil at the other end.) Push the pin beside the fold line at one end of the paper, and make a corresponding mark there. Use the mark as the pivot point for the pin, and draw an arc from the paper’s folded edge toward the outer edge. Reposition the pencil point at 15 inches, place the pin over the original mark and draw a second arc (1). These two arcs are the top and bottom of your pattern.
Place the short end of a grid ruler on the paper’s folded edge near the first arc. Slide the ruler up or down until the arc intersects the ruler at 6½ inches and make a mark. Draw a line from the pin mark to the marked point on the arc (2). The line between the two arcs completes the pattern.
Cut out your drawn pattern and unfold the paper (3).
Slab and Body
Prepare a slab large enough to accommodate all bottle parts (15×20×3⁄8 inch thick). Moving a moistened rubber rib in multiple directions, compress and smooth the slab on both sides. Spray the paper pattern with water, position it on the slab and use a pony roller to attach it firmly to the clay (4).
Cut the slab to match the template shape, using a fettling knife or an X-Acto knife with a dull blade. Bevel cut through the straight sides, assisted by a wood guide with a 45°-angled edge. Alternatively, a ruler placed along the edge of the pattern can guide the knife held at a 45° angle. One bevel is angled away from the pattern; the second is undercut so that they are parallel to one another. After cutting, peel off the pattern. Air dry the cut slab until it’s almost cheddar-cheese hard. It should stand without slumping when formed, but also remain pliable.
Wrap the remaining slab in damp fabric such as a cotton sheet. Wrapping in plastic alone causes the clay to sweat and become too soft. If leaving the clay overnight, wrap plastic over the fabric.
Score the beveled edges with a serrated metal rib and brush them with a slip made from dry shavings of your clay dissolved in water. Bring the two edges together (5). Use a rubber rib to straighten and compress the seam. Press a metal rasp to the inside seam for support while working the outside seam. Pull clay across the seam by rolling across it with a pony roller (6), then pull a serrated metal rib in various directions over the seam. Inside, run the serrated rib up, down, and across the seam. Go over both the inside and outside seam with a rubber rib. Reshape the top and bottom openings by inserting and rotating a round object such as a plastic bowl or rubber ball.
Use a Surform blade to remove any high spots on the rim. A level helps to identify these areas.
Foot and Shoulder
Stand the wide end of the bottle on the remaining slab, trace around it with a pencil or pointed tool, remove the bottle, and cut out the foot. Incise two intersecting lines using a ruler and a soft pencil with a rounded lead to create a design on the bottom of the bottle. At this time I also impress my stamp. Turn the foot over, score around its circumference and the bottom of the bottle. Slip both scored areas and attach.
Run a rubber rib around the bottom of the inverted bottle to compress the attachment area of the foot (7). Slightly push in the center of the foot, creating a concave bottom. This allows the bottle to sit solidly without rocking. The previously scored lines allow the clay to bend in more easily. Seal the seam by rolling clay across it with a pony roller, then crosshatch with a serrated rib, and compress and smooth it over with a rubber rib. Remove any excess clay with a Surform blade. Run a rubber rib around the foot’s edge at an angle for a finished undercut. Seal the interior seam using a soft lead pencil taped to a dowel (to make it possible to reach), moving the lead around the seam to create a rounded indentation.
Trace and cut a slab for the small end of the bottle to create the shoulder. Cradling the round slab in the palm of your hand, slide a finger across it to make it concave. Attach it to the opening, dome-side-up, scoring the bottle opening at an angle to fit inside the dome (8). Cut a 1¾-inch diameter opening with a cookie cutter (9). The clay should be firm enough not to buckle. Reach through the opening with one finger and compress the inside seam.
Cut a strip of clay 8 inches long by 5⁄8 inches wide and ¼ inch thick. Place it around the bottle opening, overlapping the two ends. Move the formed ring to the table, bevel cut through the overlaps, and connect the two ends. Attach the neck to the bottle. Note: Score the neck bottom at an angle to accommodate the downward slope of the shoulder. Work the inside seam with a serrated rib, then a rubber rib. Run your soft pencil around the outside seam to seal it (10). Drag a strip of moistened plastic (cut from a clay bag) around the rim to soften any sharp edges.
Fold an 11-inch square of paper into quarters. Set a compass to 5 inches wide. Place the point at the folded corner of the paper, draw an arc and then cut along this line. Unfold this paper circle and cut out one quarter of it along the folds (11). Bring the two top edges together, overlapping them 1½ inches to form a cone. Flatten this paper cone on the table, draw a line down the center and cut through the overlapping paper along the line. Attach this pattern piece to a 3⁄16-inch-thick slab (12). Cut the arc and bevel and score the two long sides. Attach a piece of moistened, lightweight plastic to the slab. As you turn the scored edges toward each other to form a cone, the plastic on the outside will become taut, compressing the clay and helping to maintain its shape. Connect the edges and work the seams as usual. Roll this formed cone on the table to reshape it, then place it in the neck of the bottle (13). To trim off excess height from the cone, stand a ½-inch wide guide (such as a strip cut from an old credit card) on the neck, and remove the clay above it.
For the plug’s top, trace the open end of the cone on a 3⁄8-inch-thick slab. Cut out this circle, curve it into a dome, attach it to the cone, and finish the seam. Rotate the domed top on the table to compress the attachment. Return the plug to the bottle. Establish a good fit by gently pushing the neck against the plug where you see spaces.
Now key the plug’s best-fit position. Make a small mark on the side of the plug and another right below it on the neck (14). Score a vertical line through the pencil mark on the neck using a sgraffito tool or soft pencil and a ruler. Remove the plug and incise a line through the pencil mark, down the length of the plug.
With a sharp tapered tool or hole cutter, make one or more breathe holes in the plug to prevent it from rupturing when fired. A wooden hole smoother adds a bevel to the inside of the hole, creating a finished look.
Create a mark-making template on a square ware board with pencil lines that divide it into quadrants and also drawn from corner to corner. Center the bottle on the board atop a turntable. Lay a pencil on its side and inscribe a line around the bottle’s base to establish the bottom boundary for the engobe.
Mix a white engobe to the consistency of heavy cream (see recipe on page 32). Inexpensive hake brushes work well for applying engobes and soft calligraphy brushes are good for tight areas and edges.
Saturating your brush frequently, apply two to three layers of engobe, each in the opposite direction from the prior. Let each layer lose its shine between applications. Clean up uneven lines or drips with a rubber-tipped shaping tool. Run a pencil around the bottom of the bottle again and around the neck-shoulder seam to reestablish engobe boundaries. Let the engobe set for several hours before the next step.
Stand a ruler on end against the bottle at each pencil line on the ware board and incise evenly spaced vertical lines through the engobe using a sgraffito tool or other round-tipped tool (15). Make randomly placed marks with the flat end of a bamboo skewer. Any crumbs created while you work are easily rubbed off when dry.
Leave the plug in the bottle and allow all to dry, uncovered and out of direct sunlight. Bisque fire in an electric kiln to cone 08–06.
Post Bisque Processes
Rinse the bisque ware with water to remove dust or clay particles. Dry the cleaned piece overnight.
As a general practice, wear latex gloves when staining, glazing, and handling raw materials.
• Stain Mix 2 tablespoons Amaco Velvet underglaze V-361 Jet Black in ½ cup water to make a stain. It should brush on like heavy watercolor paint, not opaque like acrylic paint. Cover every surface and then use a damp sponge, rinsed frequently, to wipe the stain from the surfaces, leaving it only in the textured areas (16). Dry overnight.
• Wax Resist Apply wax with a brush kept on hand for this purpose only. Brush wax resist onto the inside of the neck and around its top edge. Allow the wax to dry 6 hours. Moistening the bristles with water and rubbing them with soap will aid in cleaning the brush after use.
• Interior Glaze Apply glaze to the inside of your bottle. I used Roxy’s Chianti (see recipe on page 32), which fires to a rich transparent brown over the red clay. Pour the liner glaze into the bottle. Tilt and rotate to cover all of the interior, then pour out the excess. Use a damp sponge to clean up drips and any beading on the waxed neck. Let the interior dry for several hours or overnight before proceeding to underglaze decoration.
• Underglaze Decoration: Stamping Using full-strength Amaco Velvet underglaze V-361 Jet Black, create an overall circle pattern by dipping and stamping with a small plastic lid (17).
• Underglaze Decoration: Masking FrogTape is an excellent masking material. It’s flexible, adheres well to dry bisque ware, and keeps underglaze from migrating underneath it.
Lay out tape on a cutting surface. Using a straight edge and utility knife, cut tapered strips slightly longer than the distance between two of the vertical lines scored into the bottle. Mask each side of the vertical lines with long strips of tape and position the tapered strips horizontally within this field to create a loosely striped pattern inside of the inscribed lines (18). Run a stiff rib over all taped areas to adhere them to the surface. Brush 2–3 coats of Amaco Velvet underglaze across the masked area. Peel off the tape (19).
Let underglaze dry for several hours before glazing.
• Exterior Glaze To prevent underglaze from burning through the final glaze, first brush on two layers of Amaco LG-10 Clear Glaze. This glaze is formulated to work with underglazes and will prevent them from creating dry spots in the Transparent Cream glaze. Follow this with two layers of Gail’s Transparent Cream. Brush each coat of glaze in the opposite direction of the prior. Glaze only engobe-covered surfaces. Keep glazes 1⁄8 inch from the bottom of your piece to avoid fusing to the kiln shelf when fired. The plug and neck should be free of glaze. Finally, glaze fire the work in an electric kiln to cone 04–03.
Lisa Pedolsky is a career artist who owns Two Fish Studio in Durango, Colorado. Learn more about Lisa and her work at www.lisapedolsky.com. Follow her on Facebook at Two Fish Studio and on Instagram @lisapedolsky_twofishstudio.