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Message on a Bottle: How to Make an Ultra-Thin, Textured Slab Built Vase
Posted By Frank James Fisher On August 18, 2010 @ 7:11 am In Ceramic Decorating Techniques,Daily,Features,Handbuilding Techniques | 28 Comments
I love using stamps to add texture and interest to my work and I always enjoy searching antique shops for old printing press stamps. Frank James Fisher has an incredible selection of these stamps and I am so envious of it. Formerly a graphic designer, Frank really knows how to incorporate these stamps into his clay work to create striking images and forms.
Today, he takes us through the process of creating a stamp-textured bottle form out of very thin porcelain slabs. He not only gives insight into effectively using stamps, but he also gives some great tips for success with super thin slabs. – Jennifer Harnetty, editor.
Artists are influenced by the world around and within themselves. My ceramic art method borrows from the process of commercial printing. Stacks of old printing plates, drawers of lead and wooden type, plaster casts, and a diverse collection of textured materials fill my studio. Printing materials provide a graphic access to the raw commercial content I use to build and express a personal narrative in art. Each artwork is designed to communicate a message. In print advertising, paper is the main medium for communication, but in my art, clay is my medium.
Selecting a Clay Body
Finding a suitable clay body with properties similar to paper is a challenge. It needs to be bright white to enhance intense glaze colors. The clay particles need to be fine enough to hold delicate impressions and flexible enough for handbuilding various forms. I also feel ceramics should invite physical interaction. I want my ceramic art to be exceptionally thin and lightweight, like cardboard. Light enough to cause a reaction of surprise and amazement when handled, but also tough enough for it to be raku fired.
I use a porcelain body with molochite (porcelain grog) added. Its bright white holds impressed details, and when rolled into a thin slab remains sturdy yet flexible. Adding molochite also gives the clay the thermal shock-resistance necessary to survive the raku process.
Begin with about 6 lbs. of wedged clay and slice a half-inch thick slab with a wire-cutting tool (approximately one pound). Roughly flatten the clay between your palms, and place on a flat surface. Roll the clay into even, thin, flat sheets using the wood strips method in the side bar (see “Rolling Thin Slabs” below).
Cut all the sides for the bottle to a width of 1¾ inches. The front and back panels are a free-form rectangle with a straight bottom edge and slightly curved sides. Cut them both together by stacking two sheets of clay one on top of each other. Make extra pieces at this time in case of later unacceptable imperfections. Arrange all the pieces on a flat surface covered with newspaper, then cover them with plastic while making the impressions in the next steps (figure 1. Click on images to enlarge!).
Making an Impression
The next steps require an assortment of textured surfaces; I used a printing plate and an old gilt frame. The frame is used to texture the side and top panels. The narrow clay panels are positioned on the frame, pressed into the texture, and set aside under plastic (figure 2).
The front and back pieces are an assemblage of images made using different transfer techniques. For the main graphic, the printer’s plate, coat the surface with a releasing agent such as cornstarch or WD-40 spray. Position the printing plate face-up on the worktable. Clean the clay’s surface of imperfections and place it exactly where needed over the plate (figure 3). Begin to gently press the entire clay slab against the plate with your fingertips (figure 4). Using more pressure embeds the clay into the plate and creates an impression with more detail. This action encourages the slab to grip the plate’s surface, preventing it from sliding around and resulting in a stretched or weak imprint. A strong impression has been made when the texture of the plate begins to bulge slightly through the clay. There is a delicate balance; you need to pat the clay firmly, but not so hard that the clay thickness becomes compromised or the surface perforated. Gently outline the edge of the impression on the back of the slab with a pencil (figure 5). The outline provides a fairly precise guide for registering additional impressions made on the same slab.
After completing the transfer and outline, gently peel up a corner of the clay sheet. Look over the impression for thin or damaged spots. If you like it, keep it, if not, throw it to the reclaim and begin again.
Making additional impressions on the same slab follows the same process with the alignment being much more critical. Perform multiple impressions in immediate succession while the clay is still flexible. To create a textured background around the main graphic, position the slab over the texture positive, and repeat the process using the pencil outline as an alignment guide (figure 6). The texture can be imprinted right to the edge of the first graphic without distorting it.
Areas of an existing impression can be erased with your finger to insert smaller, additional textures. Pinch the new texture and the slab between your fingers to ensure a strong and clean impression (figure 7). Try using children’s blocks or antique lead lettering for custom text (figure 8).
Continue printing enough slabs to build a bottle form. Imprint a front sheet, back sheet, a bottom sheet, and matching top and side sheets. Imprinting the clay distorts the slab’s edge, so you’ll need to stack the front and back panels and trim the edges to their final profile (figure 9). The same is done with the sides, top, and bottom sections.
Assembling the Bottle
Wait until the slabs are stiff before assembling them. Dry them face-up under plastic for approximately 30-45 minutes or until they are close to leather hard and stiff like cardboard. If you want curved sides, bend the slabs for the side wall pieces to the desired curve and dry them on edge (figure 10).
Assemble the bottle by first joining the bottom section to one of the sides. Score and slip both surfaces, align the two pieces and slowly and gently press them together.
Adjust the walls for right angles as needed and clean excess slip from around the joint using a soft brush.
Continue working in this way, attaching the other sides. Because the clay surface has texture, use a butted-joint between the sides and the bottom. This allows the textured design to continue down the full length of the sides. If you want the sides to have a continuous design, then cut and apply the parts sequentially and the design will ‘wrap’ in one continuous pattern.
Tip: The best slip for joining clay pieces is the slurry that accumulates on your hands while throwing. This slurry is thick, sticky, and free of lumps. Whenever you’re throwing, wipe the slurry from your fingers and flick it into a lidded plastic jar.
For the shoulder of the bottle, cut the two short ends of the shoulder slab and side strips at a 45° angle. When joined, the seam is nearly invisible. Be sure to cut the opening for the bottle’s neck before joining the top panel. When lowering the back panel into position, do so carefully and don’t press the back down until you have checked its alignment. Once centered into place, gently tap the clay down along the seam and wipe away any excess slip. After the bottle is fully assembled, clean up all the joints and seams with a soft brush (figure 11).
The front and back panels often sag inward during the final assembly steps. To fix this, stand the bottle upright and inflate it by holding the bottle on the outside edges, and gently blowing into the neck opening until the front and back bulge slightly (figure 12). This will give the bottle a slightly convex front and back.
To make the neck of the bottle, curl a smaller impressed piece of clay around a narrow dowel or a tapered paint brush handle and secure the joint with slip. Add a flange to the end by wrapping a narrow band of clay near the opening (figure 13). Trim the opening in the bottle’s neck and attach it when both the neck and the flange become leather hard. (figure 14).
Slow and Even Drying
Dry the piece evenly by covering it with a plastic bag. Be sure the bag does not touch the clay. Within the bag, existing moisture both saturates through and evaporates evenly from the clay. As the moisture slowly evaporates from the clay surface, it collects on the inside of the bag. Pull off the bag for approximately an hour each day and turn it inside out. This slowly removes the moisture and provides a new dry surface for moisture to collect upon. The entire piece dries and shrinks evenly and experiences minimal stress along the seams. Continue this process until moisture ceases to collect on the plastic, then remove the plastic completely and allow it to air dry. When it reaches the bone-dry stage, it’s ready for a very slow bisque.
Make a series of matched pairs of 24-inch long wood strips cut in descending order of thickness. The thinnest pair is slightly more than 1/16-inch thick. Each pair gets progressively thicker in 1/8-inch increments, up to 5/16 of an inch for the thickest pair. The result is a successive series of thick to thin wood spacers. Paint the ends of each pair a different color to make matching them easier (figure A).
Select a pair of spacers slightly thinner than the height of the clay slab and place them parallel on either side of the clay. First roll from the center of the slab forward and then from the center backward. This divides the flattening chore into two moves, and makes for more even slabs. Next, flip it over while rotating the slab 90° (figure B). This method of roll, flip, and turn is a critical step and helps eliminate warping during the drying process—continuing to roll the slab in the same direction may cause the clay to curl like a potato chip as it dries. Substitute the next thinner pair of spacer strips and repeat the rolling process including the roll, flip, and turn. Continue this process, working through each consecutive spacer strip until the resulting clay slab measures 1/8-inch thick (figure C).
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