About the Process of Making Bas Relief Tiles

I’m “the chief cook and bottle washer” here, which is to say, I do absolutely everything involved with the creation of the work I sell, from the original sculpture to the firing. I used to have helpers when I did more fine art and crafts shows, but have not had any in several years.

All of my designs, except those that are one-of-a-kind, begin with the creation of sculpture in modeling clay (Plasticine or Plastolina), which is an oil and wax-based clay that never dries out or hardens. This allows me to work as long as necessary to finish each sculpture exactly as I want it to be. When it is done, I make a plaster waste mold from it, and from that mold, I make my master mold. It is an exact copy of the sculpture in a very hard, dense type of plaster. The sculptural details can be further smoothed and refined for three or four days after the plaster hardens but before it fully dries. Once that is completed, I coat the mold with a special soap that polishes it and acts as a separating medium, allowing me to make pouring molds in a lighter, more open type of plaster which is better suited to absorbing water from the liquid clay slip that is poured into the final molds to make the actual tiles. I roll out slabs of clay of the proper thickness, lay them into the molds for the fronts of the tiles, shape the back sides so that they will resist slumping when the freshly cast tiles are removed from the molds, trim them, and pour plaster against them to create the back halves of the molds.

I make my own stoneware slip from a special dry clay recipe (formulated for me by my clay supplier) mixed with deflocculants, and water . Deflocculants are chemicals that make the clay become liquid with the addition of a minimum amount of water so that the plaster will not become saturated before the slip has become dry enough to hold its shape when removed from the mold.

The clay must be dried slowly and evenly to prevent warping and cracking. Sculpture that is large, of uneven thickness, or has very delicate parts requires special care during drying. The sculpture can be modified in various ways at particular stages in the drying process. The clay is not ready to be fired until it is bone dry.

I fire all of my work at least twice; a bisque firing to get it ready for staining and/or glazing, and a high-firing to mature it to its final color and finish. Some finishes require additional firings. After a bisque firing the clay is salmon-colored and firm, but not very strong. I carefully apply stains and sponge off the excess. Stains emphasize the details of the sculpture. I paint glaze into detail areas such as the eyes or talons, and then paint liquid wax over the those areas and any areas where I want to preserve the color and texture of the unglazed clay. Wax prevents successive layers of glaze from sticking very well but it is still necessary to carefully wash off unwanted drips.

The clay shrinks about 13% from the time it is cast in the molds until the final firing is complete. Part of the shrinkage is due to the loss of water during drying, and part of it is due to the loss of chemical water and vitrification during the firing – the clay changes in structure and becomes much more dense and durable during high-firing.

I, of course, try to control everything as much as possible to ensure the results I want, but the kiln does what it wants to; I cannot control all of the variables. Opening the kiln is always a surprise – sometimes a joy, sometimes a real disappointment, and, every-so-often, a minor miracle. I do my best to learn from whatever happens.

Leave a Reply

Your email address will not be published. Required fields are marked *