Tiles have a fascinating history, and the art of making and designing them can give you the satisfaction of working with your hands. Here, we will take you step-by-step through the process of preparing a tile slab. Tools you will need include cutoff wire, two strips of wood, canvas, smooth board or wallboard, a rolling pin, a metric ruler, a straightedge, a pencil, cardboard, pin tool, and clay. Access to a kiln—a special heating chamber—is also important. Standard kitchen ovens don’t get nearly hot enough to harden clay for tile.
You should be extremely conscientious about keeping your tools and equipment clean and your workspace properly ventilated. The air can get quite dusty when you’re making tiles. The kiln also should have proper ventilation. Be sure to protect your eyes with infrared-blocking goggles when you gaze into a hot kiln, and remember that pieces coming out of the kiln are extremely hot.
Once you have the equipment, and have taken the necessary precautions, you’re ready to begin making your own tiles.
To make your slab, first wrap a piece of canvas over a flat board. Using the cutoff wire, slice a piece of clay 2' to 3' thick. Immediately put the leftover clay in a bag. If you leave it out, it will get dry and crumble.
Place the piece of clay you cut off on the canvas-covered board and pound it flat with the palm of your hand. Place one wood strip on each side of the slab to help you roll it into uniform thickness. Lay another piece of canvas over the slab and place the rolling pin on top of the strips. Roll until the slab is even in thickness.
Next, transfer your slab to another flat surface for measuring, cutting, and drying. To do this, place a piece of wallboard on top of the slab, then carefully flip the slab, which is between the wallboard on top and the canvas-covered board underneath. Transferring your slab this way will keep it from stretching out or losing its shape.
Your original tile must be larger than you want your final product to be because clay shrinks when dried or fired. Each type of clay has a different percentage of shrinkage—a lot depends on the temperature it’s fired at and the amount of filler—sawdust, sand, or straw—in the clay. Here is a method to determine shrinkage.
Make test strips from the clay you plan to use for your tile and fire them at the temperature you will fire your slab. Each test strip should be about 11/2 inches wide, 6 inches long and 3/8 of an inch thick. Use a straightedge and a pin tool to cut your test strips. Measure each strip at 10 cm using your metric ruler. Be sure to mark the soft clay with the cone number from the kiln you’ll fire that strip at, and also make a note of the type of clay body from which the strip was cut. Measure the strips after they are fired and you can calculate the shrinkage.
Cutting Tile Shapes
A pin tool works better than a regular knife when cutting standard square or rectangular tiles because the pin won’t veer off course—it has no tendency toward an angle as a knife does. One way to cut flat tile shapes is to create a template of the shape you want from either cardboard, mat board, or thin Masonite. Trace the template with your pin tool on the slab and cut it out.
The next trick is to get your tile to dry and fire flat without warping. Clay is called leatherhard when it is predominately dry but has enough moisture to be impressionable. Tiles that are bone dry are uniform in color and tone and dry to the touch. Be careful when you are handling bone dry tiles. They are very delicate and brittle.
If you leave tiles on a wooden board to dry, the top will dry faster, and shrink faster than the bottom, and the tiles will warp. You can make sure your tiles dry slowly and evenly by covering them with a sheet of plastic for at least 24 hours and then loosening the plastic so air reaches the tiles slowly.
Adapted from Handmade Tiles by Frank Giorini. Copyright ©1993, Frank Giorini. Lark Books, 50 College St., Asheville, NC 28801. (800) 284-3388.