clay bodies explained
l.04 · 7 minute read · updated July 2026 · by the studio
A clay body is a recipe: natural clays blended with minerals so the mix throws well, dries evenly, and fires to a known temperature. The bag label tells you almost everything that will happen to your work months later, which is why it is worth learning to read before anything else in ceramics.
the four families
| body | fires at | character | for beginners? |
|---|---|---|---|
| earthenware | cone 06 to 02 (about 1000 to 1120 C) | porous, warm colours, chips easily, must be glazed to hold liquid | fine, especially for hand building and colour work |
| stoneware | cone 5 to 10 (about 1180 to 1300 C) | vitrifies dense and tough, dishwasher-proof, the workhorse of functional pottery | yes. this is what most australian studios hand you |
| porcelain | cone 6 to 10 | white, translucent when thin, memory for every touch, collapses if you look away | no. earn it in year two |
| raku | removed glowing at about 1000 C | open, thermal-shock resistant, crackle surfaces, strictly decorative | only in a guided raku workshop, which you should absolutely do once |
shrinkage, the number nobody warns you about
Clay shrinks twice: as it dries and as it fires. Total shrinkage runs 10 to 15 percent depending on the body. Your generous mug becomes a modest one, and the lid you measured to fit does not. Every bag lists a shrinkage percentage; potters make test tiles and measure, or reach for a shrinkage calculator. If you ever wonder why handmade lids fit loosely or perfectly and nothing in between, shrinkage is why, and it is also part of why handmade ceramics cost what they cost.
grog, speckle, and what 'toothy' means
Grog is pre-fired clay ground up and added back for strength; it makes a body 'toothy', more forgiving on the wheel and less prone to warping, at the cost of a rougher surface. Iron speckle burns through glazes as dark freckles, which is exactly the effect on several pieces in our catalogue. Smooth bodies take crisp detail and show every fingerprint. None of this is better or worse; it is palette.
matching clay to firing, or how pots die
The fastest way to ruin a kiln shelf is firing earthenware to stoneware temperature; it melts. The fastest way to make fragile pots is the reverse: stoneware fired to earthenware temperature never vitrifies and drinks water forever after. Your clay, your glaze, and your firing must agree on a cone. What cones actually are, and why this studio fires to cone 10, is the whole subject of firing and cones.
common questions
what clay should a beginner potter buy in australia?
A mid-fire (cone 5 to 6) speckled stoneware with some grog, from a ceramics supplier like Keane's, Walker Ceramics, or Clayworks. About $25 to $40 per 10 kg bag.
what is the difference between pottery and ceramics?
Ceramics is the umbrella term for anything shaped from clay and hardened by heat. Pottery usually means functional vessels. All pottery is ceramics; not all ceramics is pottery.
why does clay shrink when fired?
Drying removes water between clay particles, pulling them closer. Firing then fuses the particles and closes remaining pores. The two stages together shrink most bodies 10 to 15 percent from wet to fired.
can you fire clay in a home oven?
No. Domestic ovens reach about 250 C; the weakest true ceramic needs around 1000 C. Oven-bake craft clays are polymers, not ceramic, and are not food safe.