Firefly Pottery
Pottery Terminology

Pottery Terminology

If you have a knowledge of pottery our website content is easy to follow, but if not it can be gobbledy gook! So lets see if we can help.


Clay – the material with which we work comes in different varieties, the differences being their mineral content, platelet size , plasticity and firing temperatures.

Earthenware clay

White buff or terracotta in colour a low to mid fire temperature clay.

Porcelain clay

White with translucency achievable, very high fire temperature clay.

Stoneware clay

White, buff, red, black, specked, a high fire temperature clay.


Liquid clay used for moulds, stained for greenware colour application, mixed to use as glue to bind clay elements together when constructing.

Stages of clay


This is a term used to describe the first stage of clay make – when a shape has been formed but not yet fired.

Leather hard

This describes a condition of clay when it has been partially dried, to the point that shrinkage has been completed, having the consistency of leather and retaining about 15% of it’s moisture.

Bisque or biscuit

This describes pottery that has received its first firing and is ready for glaze application.


Pottery that has received its final firing and is ready for use.



This is the ‘oven’ if you like, in which the clay is fired kilns can be powered by wood, gas or electricity reaching top temperatures of around 1300 degrees it’s somewhat hotter than your household oven! Fireflys kiln is Electric.

Bisque fire

This is the first firing the clay gets to turn greenware into ceramic material. Clay must be completely dry to go into this firing. Bisque or biscuit fired pots are hard and porous – which means if they get wet they will absorb water.


The term used to describe the process in the kiln of turning clay into ceramic material by heating it to mature the clay into ceramic.

Glaze fire

After the bisque fire glazes can be applied, painted or dipped on, and a second firing – the glaze firing can be done. During this firing the glaze and clay undergo a lot of changes that result in the clay maturing and the glaze melting to the clay surface forming a bond that results in a glass seal that colours and waterproofs your pot.

Drying times

Making with clay to bisque fire

It can take anywhere from a week to a month to dry out pots ready for a bisque fire this is affected by pot size and thickness and the weather. This makes completion times variable – which is why we ring you after the bisque fire to let you know when pots are ready.

Glaze painting to glaze fire

Underglaze brush on or dipping glazes need 24hrs to dry it may then be dipped in a clear glaze – which then needs a further 24hr to dry before firing. This set process timescale allows us to provide the promise of pick up a week from your glazing visit (unless we let you know otherwise) and why we have no need to contact you after glaze sessions.

Making – Session types

Pottery wheel

This is a machine used for creating and shaping of round ceramic ware – pots, they can be manually powered (kick wheels), or electrically powered. Some you sit on, some have a separate stool, at some you stand. We have a selection of different electric wheels at Firefly to provide the opportunity to experience a range of makes and models to see what suits you best.


This is the term used for creating pottery on the pottery wheel.

Pottery painting

This is a term used for the painting of pre made items of pottery. These are moulded items that range from figurines to mugs bowls plates money boxes a raft of household and decorative pottery that has been bisque fired ready for you to paint with underglaze.

Hand Building

This is an ancient pottery technique used to create forms without a pottery wheel using your hands and simple tools. There are range of hand building techniques which include pinch pots, coil pots , slab built pots and modelling (sculpture).


This is a term that covers adding colour to your pottery, glazes can be applied by brushing, dipping or sponging . There are a huge range of types of glazes – underglaze paints and pencils, crystalline glazes, oxides, stains, decals. Then theres a raft of techniques of use to try layering, bubbles, stencils, sgraffito etc.