# The Rules of Bisque Loading

Unit: The First Bake: Bisque Firing
Topic: Loading a Bisque Kiln
URL: https://claybook.studio/learn/the-rules-of-bisque-loading/

# Packing the Kiln Smartly

A well-loaded bisque kiln is a dense, efficient kiln. Because bisque-fired pieces have no glaze, they will not fuse to each other, which means you can pack them far more tightly than in a glaze firing. This is one of the great advantages of the bisque step.

## The Golden Rule of Bisque Loading

**In a bisque firing, clay can touch clay.** You can stack pots inside each other, nest bowls rim to rim, and fill every available cubic centimetre of space. No piece of kiln furniture needs to separate pots from each other, only from the shelves and kiln walls.

This is the opposite of glaze loading, where every glazed surface must be kept separate.

## Nesting

Nesting means placing smaller pots inside larger ones. A large bowl can hold several small cups inside it. A cylinder can have a smaller cylinder inside it. Each nested piece reduces the number of shelf levels you need.

Rules for nesting:

*   The pots inside must clear the rim of the outer pot; they cannot protrude above it, or the shelf above will hit them.
*   Nesting works best with similar forms: bowls inside bowls, cylinders inside cylinders.
*   Do not overfill a nested form; you still need to be able to retrieve pieces after firing.

## Stacking Rim to Rim

Two bowls of the same diameter can be placed rim to rim. The upper bowl rests on the rim of the lower, and both are supported. This doubles the number of pieces per shelf level.

## Bisque Packing Checklist
Before closing kiln:
* Confirm nested pieces clear shelf above
* Keep peep/cone view unobstructed
* Verify no piece touches kiln wall/elements

Dense loading still needs airflow and visibility.

## Keep Exploring

Dense bisque loading is possible because unglazed clay does not undergo [vitrification](https://en.wikipedia.org/wiki/Vitrification) at bisque temperatures, so surfaces cannot fuse together. For more on the kiln structures that support all those nested pots, the Wikipedia article on [kilns](https://en.wikipedia.org/wiki/Kiln) covers the design of both intermittent and tunnel kilns used in studio and industrial ceramics.

## Check your understanding

### Question 1: Why can clay pieces touch each other during bisque firing?

- [ ] A. Bisque temperatures are too low to cause fusing
- [x] B. Without glaze, pieces cannot fuse to each other
- [ ] C. Clay shrinks away from other pieces during firing
- [ ] D. It is fine as long as they are the same clay body

Tip: Because they have no glaze, unfired clay pieces will not fuse together when they touch, unlike glazed pieces in a glaze firing.

### Question 2: What is the rule for nesting pots inside each other for bisque?

- [ ] A. The nested pots must be the same weight
- [x] B. Nested pots must not protrude above the outer rim
- [ ] C. Only the same clay body can be nested
- [ ] D. No more than two pots can be nested

Tip: The nested pieces must not protrude above the rim of the outer pot, or the shelf above will hit them.