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Photo: Natalie Wilson / Flickr

It may be surprising to know that the oldest surviving ceramics are not pots but Eastern European votive figures which were fired around 30,000 years ago. Unfired figures may well have been made in even earlier times but they couldn’t have survived without the hardening of fire. The desire for working in clay has not waned to this day. Bryan Sentance discusses clay modelling techniques in his book Ceramics: A World Guide to Traditional Techniques. He begins by explaining the required consistency.

Correct consistency for clay work

‘Just handling clay subtly alters its form. Slight changes wrought by pressing and squeezing fire the imagination and prompt further manipulation, pushing, prodding and pulling until a recognisable shape appears,’ says Sentance. But to do this, the clay must be of the right consistency: not too dry so that it cracks and not so wet that it sticks to your hands.

Additive clay modelling

It is easy to add more clay to an original work when the clay is still in its plastic state. The new sections can be incorporated by pressing them together. The surfaces can then be smeared together so that there is no sign of a join.

For more complex creations, it may be easier to work on separate sections and then join them together when they’re firm enough to hold their shape. ‘In this case, it is necessary to employ a process known as luting in which both surfaces must be roughened or scored before “gluing” together with a thick slip or slurry.’

Subtractive clay modelling

If the form needs refining when it’s still in the plastic stage, sections can be cut away with a modelling tool or they can be pinched away with the fingers. This is not the case for the leather-hard stage as the harder clay requires sharper tools ‘and the action becomes more sculptural as carving creates clearly defined surfaces and sharp edges.’

The leather-hard stage is the point at which it is best to add detail to a piece. Once the clay reaches the chalky stage, the sculpted work will flake away.

Hollowing the clay

All models should be hollowed, except for the smallest ones. That’s because a solid form will shrink unevenly as it dries out. It can also easily crack before and during firing. The chances are it may explode in the kiln. ‘A small hole will allow the passage of air as the object expands,’ explains Sentance.

Sentance continues to say that the problem can be avoided by modelling ‘on to a hollow form that has been pre-shaped, for example, from a pinch pot or a slabbed cylinder.’ A leather-hard object can be cut in half and the insides spooned out with a spoon (or a looped wire). The pieces will then have to be put back together by luting them.

The work can then be decorated and fired.

Other forming techniques include pinching, slab building, coiling, paddle and anvil, throwing, moulding and slip casting.

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