Frequently Asked Questions about Sweets
Tradional Vase by David Green

A Potted History of Ceramics

10955436_10153281868339390_651796831336795475_n When you paint a piece of pottery in Jenny's Painted Pots you are doing the same thing as your oldest ancestors would have done, and although the technology has changed a little, the principles have remained the same.

Ancient_pots
Ancient pots from Judea thought to be from around the time of Moses.

Pottery has been made in most parts of the world for at least 10,000 years, in fact the oldest pottery is from China and is over 20,000 years old; well before farming began and while the last ice age was still going strong. Pottery is one of the things found by archaeologists and used as evidence that humans lived in a certain place. Pottery was popular because it helped our ancestors to make useful containers to hold and carry water or to serve food and drink. And once people had got used to making pots for useful things, they started to decorate their pots and to make objects which were more decorative than useful. This was the case particularly in the homes of important people.

Normally we think of pottery as something which is made using clay. This is soft and moist and found in the ground mixed in with other things in the ground. The other things in the ground, for example chalk, will make the clay lighter or darker. When the clay is soft it can be shaped, it is then 'fired' in something called a kiln, which is like an oven, but much much hotter than one used for cooking food. Once the clay has been cooked in the kiln it is hard and holds it shape and it can hold water.

Decorated_ancient_pots
Decorated pots from ancient Corinth in Greece.

When you paint a pot in Jenny's you are painting the clay after it has been fired. It is called a 'bisque' at this stage. After you have finished painting, your bisque is glazed and then fired in the kiln again. Glazing is what makes the pot shiny and smooth and the colours you used to paint become more vivid.

Persian Glazed Pot
Glazed pot from Persia in the 16th century.

Glazing is a much more recent process than making pottery, it is more like 10,000 years old. It became popular because it made pottery even stronger and much less porous, so it could hold water without it gradually seeping thought the clay and onto the ground.  Glazes have been made from a variety of materials and most people think that glazing was discovered rather than invented.  Some suggest that 'potters' tried various materials in their kiln and then noticed with some materials, for example sand, that the material almost melted and became shiny. The suggestions is that then they tried to coat the clay pottery in these materials. Glazes all have three essential ingredients, silica which becomes the 'glass' that you see as the glaze on your pot, alumina (aluminium oxide) which makes the silica stick to the clay and a 'flux' (a metallic oxide) which lowers the melting point of the silica to something that a normal kiln can reach. While ancient glazes were often harmful, the ones used by Jenny's are completely non-toxic.

 

 

 

 

Roman Kiln
Diagram of a kiln from Roman times.

The kiln used by the staff at Jenny's uses electricity to heat the pot. It is typically heated to about 1,200°C which is four times hotter than the hottest setting on a home oven. The 'cooking' or firing takes about seven hours, and then about another seven to cool down enough to touch the pot. Our stone age ancestors didn't have electricity, they had to use fire to heat their kilns. Their kilns would have been pits dug into the ground and covered in the hottest burning material around, charcoal. This is made by burning wood and restricting the amount of air around during the burning. Charcoal would burn much hotter than wood when it was burnt.

 

The kiln used by Jenny's will hold about 20 items of pottery. This is enough for a small craft studio, but it would not do for producing useful quantities of plates and cups and saucers. So you can imagine that kilns can get to be quite large. The largest kilns are tunnels which you can drive into, but they really come in all shapes and sizes. 

Evenheat Rampmaster II as used by Jenny's Painted Pots
The type of kiln used at Jenny's

So, that is a bit of background on the ancient craft you are getting involved with. The basic ingredients of clay, paint, glaze and heat are the same as those used over many thousands of years. They have been brought up to date as technology has improved and any harmful impurities have been removed. But if you find yourself wondering what decoration to put on a pot, you may well be having ideas similar to those of your ancestors.

There is something very therapeutic about being a 'potter' and for some people it may start you off on a creative path which will last a lifetime. We certainly hope so.