01 of 07
Prepare to Throw Your Plate
From a beginner's or non-potter's point of view, plates can seem to be one of the easier forms to make. The reality is a bit different. Because they have such a large floor, especially in relation to the plate's rim, S-cracks are a strong possibility. Throwing plates is a good way to test your potting skills.
Each plate will take about one to two pounds of clay, although you may want to throw using slightly more. This excess clay will allow you to keep a thick floor, which in turn... allows you to trim out a foot ring when the plate is leather hard. Tools you will probably want include a potter's needle, piece of chamois, sponge, wooden trimming tool, a rubber or wooden rib, and a large loop tool.
If you are making plates that could at all possibly be used with food (even if your thought is for it to be only decorative), be certain that you are using a mid-range or high-firing clay and glazes, and that your glazes are both food safe and have a gloss surface. If you are throwing sets, make sure you have enough clay and glazes on hand to complete the number of plates desired.
Get ready to throw: check your fingernails, gather your tools, and set up your water and slop buckets. Thoroughly wedge your clay. If throwing multiples, it is to your advantage to wedge all your clay before sitting down to the wheel.Continue to 2 of 7 below.
02 of 07
Center and Open the Clay
When centering the clay for a plate, form the clay into a low dome. By centering low, you make it less likely that the clay will fold over itself as you open. You wish to avoid this since it can trap pockets of air either in the clay or between the clay and your bat.
If you want to be able to trim out a foot ring, be sure to leave enough clay as you push your opening into the clay. Bear in mind that the cut-off wire will usually "lift" a bit in the middle of the cut when such a large... floor is involved. Leave enough clay on to also compensate for this loss.
Open the clay slowly, especially as you pull outward, creating the floor. All movements need to be gentle as you engage the clay and as you release it. Any sharp changes in pressure can easily throw your plate off center. This will show up quite noticeably as you form the rim of the plate.
Open your floor as wide as you desire. Before moving on to the rim, it is time to compress the floor.Continue to 3 of 7 below.
03 of 07
Compress the Thrown Plate's Floor
Clay is made of platelets. Uneven shrinkage can cause warping and cracking. By compressing the platelets the clay will shrink uniformly, which reduces the possibility of both warping and cracking. A pot's walls are compressed through the action of throwing, but the floors do not go through that process. All too often, if a plate's floor is not compressed enough, an S-crack will form.
To ensure even shrinkage, compress the floor of your plate. As you see in photograph, you can do this by... applying gentle pressure with your hands or by applying gentle pressure with a rubber rib. Wooden ribs can also be used, but they require more care to make certain you do not cut into or scrape up the clay.Continue to 4 of 7 below.
04 of 07
Throw the Plate's Rim
Slowly pull the rim of the plate outward. The motion to do this may be more similar to straightening the walls of a pot rather than throwing them, depending on how broad the rim is.
Make certain to keep the wheel revolving very slowly and support the rim's underside as you work. Do not overwork the clay, or the rim is very likely to collapse. Be certain to compress the edge of the rim with a piece of damp chamois. Also, clean up any slurry from the plate's floor.
While the plate is on the... wheel, you can also define the plate's sections, if desired. For example, in the photograph you can see I am using a wooden trimming tool to emphasize the demarcation between the floor and rim.Continue to 5 of 7 below.
05 of 07
Cut the Plate Off the Bat
If you are planning on trimming the bottom of the plate when it is leather hard, do not worry about trimming excess material away at this point. You are more likely to damage the rim by doing so. If you are not planning on trimming the plate later, do trim away the excess now using a wooden trimming tool, but be very careful and work slowly.
Cutting the plate off the bat can be problematic. For the best results, use a cut-off wire or line that has a wooden handle at each end. Wrap the wire around... the handles until you have just enough line to go from side to side of the plate, plus two inches.
You will be cutting from the side opposite from you, moving toward you. Set the wire on the bat with it pulled as taut as possible between your thumbs. On the photograph, you can see how much pressure I have on my thumbs, both outward and downward. Keep as much tension on the wire as possible throughout this step.
With the wheel moving very, very slowly, slide the taut line along the bat and under the plate. Cut halfway through. You will be able to see where the line is on the floor of the plate. Once you have reached the center of the plate, reverse direction and slide the taut line back out to the edge of the bat opposite you.
By pulling the cut-off wire only halfway toward you and then back the way it came, you are less likely to inadvertently raise the wire off the bat as you come closer into your body.Continue to 6 of 7 below.
06 of 07
Dry, Trim, and Decorate Your Plate
Do any slip trailing or other slip decorating before moving the plate's bat to the drying rack. (Most techniques using slip work better if the slip is applied while the clay is still damp. When using a commercial underglaze, check the manufacturer's directions on how to apply.) If you are doing stamping, dry the plates for a time until they have stiffened up to a soft leather-hard.
Dry plates very slowly. After moving the bat to a shelf, cover the wet plate very loosely with a light... plastic sheet --- you want the plastic to touch the plate as little as possible, if at all. Plastic grocery bags and dry cleaner bags work well for this.
Once the plate has reached leather hard, very carefully remove it from the bat. Plates will often want to stay on the bat, so very gently coax the plate upward, spreading your hands to support as much of the plate's rim and bottom as possible. You may find it helpful to put the bat back on the wheel and very, very slowly rotate the bat while keeping the plate still and supported with your hands.
If you are trimming a foot ring, do when the bottom is leather hard. You may need to invert the plate on a smooth shelf or ware-board and let the bottom stiffen up a bit more. If this is the case, again lay plastic over the plate to slow down and keep drying even.
If you are going to be doing a lot of plates or other pots with trimmed foot rings, seriously consider getting a trimming system such as the Giffin Grip. Also, remember to always use sharp loop or ribbon tools for trimming. A dull tool makes you work harder, and can adversely effect the quality of the trimming job.
If you are going to do any decorating at the leather-hard stage, do this after the plate has been trimmed. Such decorations may include incising, fluting, and so on.
Continue drying the plate slowly. For best results, place the plate on a sealed piece of drywall and covered loosely with plastic until bone dry.Continue to 7 of 7 below.
07 of 07
Bisque, Glaze, and Fire Your Plate
Once your plate is bone dry, it can be bisque fired. When loading the kiln, be careful not to allow the plate's bottom to overlap any joints between kiln shelves. The slight movement of the ware and the shelves during firing can put enough stress on the floor to cause it to crack.
After it has cooled and been unloaded, you can glaze your plate. Again, make certain to match the glaze maturation temperature and the clay body's maturation temperature. Also, only use food-safe gloss glazes.In... our example plate, two different mid-range blue glazes have been used. The dark blue was not only used for the rim but also trailed across the surface of the floor after the turquoise glaze had been applied.
Once the applied glazes have dried completely, your plate is ready for its glaze firing. After it has cooled and been unloaded from the kiln, it is ready for use.