How to Throw a Plate That Doesn't Crack or Warp
A plate looks like the simplest thing you could throw: a flat disc with a rim. In practice it fights you at every step. The wide floor sags, the rim wobbles and the whole thing cracks or warps in the kiln.
Plates are hard because a large flat area has nowhere to hide its stress. The good news is that a few habits fix most of the trouble.
Why plates fail
- A thick floor dries slower than the rim, so it shrinks later and cracks.
- Unequal compression leaves tension that shows up as S-cracks or warping.
- A heavy edge drags the rim down or out of round.
- Fast, uneven drying curls the rim.
Everything in the process is about making the clay as even and compressed as possible. See why plates are hard for the full explanation.
Step by step
1. Start with enough clay. A small plate starts around 500 g and a dinner plate around 750 g, depending on your clay and diameter. Weigh your balls so your plates match.
2. Center very well. A wobble in the first step will be magnified in the rim.
3. Open flat. Press down and out to make a wide, flat floor. Keep the floor level, not dished.
4. Compress the floor. Run a metal rib across the whole surface while the wheel turns, working from the center out several times. Compression aligns the clay and is your best defense against cracks.
5. Set the thickness. Aim for a floor thickness of roughly 6 to 8 mm (a little under 1/3 in) for dinner plates, slightly thicker for large platters. Check with a needle tool.
6. Raise the rim. Lift the outer edge with a gentle push up and out, with a wide angle. A shallow rim is easier and more elegant than a steep one.
7. Shape and compress the rim. Use a sponge or your finger to round the edge and compress the lip.
8. Cut off carefully. Slide the plate off the bat or use a wire at a shallow angle. If you can, throw on a bat so you never need to lift it by hand.
Dry slowly and evenly
Dry plates slowly, under plastic for the first day. Then:
- Place them on a flat board or drywall that wicks moisture.
- Flip them over once the surface is firm to dry the underside.
- Cover the rim for a day or two so it does not dry faster than the floor.
Drying is covered in more depth in dry a plate without warping.
Trim with care
Trim at leather hard, as for any form. A foot ring gives a plate stability and a place to hold it, and also removes weight. Our guide on trimming a foot ring covers the details.
Plate troubleshooting
- Floor cracks in the center: floor too thick or compression missing.
- Rim waves in the kiln: rim dried too fast or the wall was thick on one side.
- Plate looks dished: floor not flat when opened or bowl-like curve pulled in the rim.
- S-cracks on the underside: uneven drying. See why pottery cracks.
Make a set
Throw a set of four identical plates for a real test. Weigh each ball, use the same rib pressure and note the diameter before and after. Logging weights and dimensions in Claybook lets you repeat the plates you like.