# Pottery Vocabulary

Part of the Pottery Merit Badge Digital Resource Guide: [Introduction & Overview](https://merit-badge.university/merit-badges/pottery/guide/index.md)

> **4.** Explain the meaning of the following pottery terms: bat, wedging, throwing, leather hard, bone dry, greenware, bisque, terra-cotta, grog, slip, score, earthenware, stoneware, porcelain, pyrometric cone, and glaze.

Pottery has a lot of special vocabulary because clay changes so much from start to finish. Some words describe tools. Some describe materials. Some describe stages in a piece's life. If you can explain these terms clearly, you will sound like someone who understands the process instead of someone guessing from the outside.

## Tools and working methods

**Bat** — A removable round or flat surface attached to the wheel head. Potters use a bat so they can lift a freshly thrown piece without touching and warping it.

**Wedging** — Kneading clay to even out moisture, remove air pockets, and align the clay so it behaves better while building or throwing.

**Throwing** — Shaping clay on a spinning potter's wheel with your hands and tools.

**Grog** — Fired clay that has been crushed into gritty particles and mixed into clay bodies to add strength and reduce shrinkage.

**Slip** — Clay mixed with water until it becomes creamy or liquid. Slip can be used for joining, decorating, or coating surfaces.

**Score** — Scratch or roughen two clay surfaces before adding slip and joining them. Scoring helps the pieces lock together.

> **Tip**
>
> A good memory trick is this: **score and slip** go together. Scratch first, then add the wet clay mixture, then press the parts together.

## Stages of drying and firing

**Leather hard** — Clay that has dried enough to hold its shape but is still damp enough to carve, trim, or attach pieces.

**Bone dry** — Clay that feels room-temperature dry and has no visible moisture left. At this stage it is very fragile.

**Greenware** — Any unfired clay object after it has been formed and dried.

**Bisque** — Pottery that has gone through its first firing. Bisque ware is harder than greenware but still porous enough to absorb glaze.

**Pyrometric cone** — A small cone made of special ceramic material that bends at a known heat-and-time combination inside the kiln. Potters use cones to measure how much firing work the kiln has done.

> **Safety First!**
>
> Bone-dry ware looks sturdy, but it can snap or chip very easily. Handle greenware and bone-dry pieces with two hands and a clear path to your shelf.

## Clay families and surfaces

**Terra-cotta** — A reddish-brown fired clay, often low-fired, commonly used for flowerpots, tiles, and traditional earthenware.

**Earthenware** — Clay fired at a lower temperature. It is often more porous and can include terra-cotta bodies.

**Stoneware** — Clay fired hotter than earthenware, making it denser and stronger. Many mugs, bowls, and dinnerware pieces are stoneware.

**Porcelain** — A very fine, smooth clay body that fires hard and often white. It can be beautiful and translucent, but it is less forgiving to work with.

**Glaze** — A glass-like coating that melts onto pottery during firing. Glaze can add color, texture, shine, food-safe surfaces, or waterproofing.

**A useful way to organize the terms** — Group them by what they describe

- [ ] **Tools and methods**: bat, wedging, throwing, score, slip
- [ ] **Drying and firing stages**: leather hard, bone dry, greenware, bisque, pyrometric cone
- [ ] **Clay types and surfaces**: terra-cotta, earthenware, stoneware, porcelain, glaze, grog

## Official Resources

Video: [Ceramics 101: Clay Vocabulary and Processes (video)](https://youtu.be/OdUBdRI3Iyw?si=agyum4noQ3XJTzH7)

[Ceramic and Pottery Glossary (website)](https://lakesidepottery.com/HTML%20Text/Tips/A%20pottery%20glossary.htm): A browseable glossary you can use to review unfamiliar pottery terms before talking with your counselor.

> **Be Prepared! If you forget a pottery term in conversation**
>
> Do not panic or guess wildly.
>
> - **Step one**: Connect the word to where it fits in the process.
> - **Step two**: Describe what it does or when it happens.
> - **Step three**: Use a real example from your own project if possible.

Req 5 puts this vocabulary to work. You will hand-build, sculpt, throw, and think about firing, so words like leather hard, score, bisque, and glaze will stop being definitions and start becoming real steps.

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- Previous: [Drawing Pottery Forms](https://merit-badge.university/merit-badges/pottery/guide/req3/index.md)
- Next: [Build, Throw, and Fire](https://merit-badge.university/merit-badges/pottery/guide/req5/index.md)