From Lump to Flat Form
Now that you know the pitfalls, here is exactly how to throw a plate that survives.
Clay Weight and Centering
Plates need more clay than you think for their height. A 25cm dinner plate might use 1.2–1.5kg of clay. Center it low and wide: a flat, stable disc, not a tall mound.
Opening Wide
Open aggressively. Push outward more than downward. The floor of a plate should span almost the entire width of your clay mound, leaving only a small amount of wall at the edge.
Stop frequently and compress the floor. Then compress again. Then one more time. Use the flat pad of your finger, pressing in slow, firm circles from center to edge.
The Walls
A plate's "walls" are actually just a raised rim: 2–4cm tall. Pull them with only 1–2 passes. The rim should be slightly thickened compared to the floor, not thin.
- Pull the rim up and very slightly inward to give it structural integrity.
- A rim that flares outward collapses during drying.
Fighting the S-Crack
After every stage of opening, compress the floor thoroughly. The S-crack forms because the spiral pattern from opening leaves clay particles in opposing directions. Compression disrupts this pattern and realigns the particles.
This is the single most important step for a crack-free plate.
Drying
Wire the plate off immediately and move it to a dry bat. Place it on a sheet of newspaper or foam, not a plaster bat, which can dry the base too fast. Cover the rim loosely with plastic for the first 12 hours.
Warping Prevention Checklist
During first 24 hours:
- Keep airflow gentle and even
- Protect fast-drying rim
- Recheck flatness before full uncovering
Most plate failures happen in drying, not on the wheel.
Keep Exploring
The S-crack problem is closely related to how capillary action draws moisture unevenly through clay as it dries, creating internal stresses that exploit any weakness in particle alignment. Different clay bodies respond differently to these forces; earthenware clays, for example, tend to be more forgiving than porcelain when it comes to flat forms because of their coarser particle structure.
