Hi Everybody,

Before glazes, the method used to make pottery watertight was by burnishing clay and then rubbing in some wax, but the true origin of glaze dates back to 5000 BC. The Egyptians were perhaps the first to discover that glass and sand impregnated with salt fused into glaze. These glazes were used for decoration purposes only. It wasn’t until 1500 BC that glazes were used for hygienic and waterproof purposes.

The earliest glazed objects are painted with what is known as Egyptian paste and the main ingredients are sand silica (silica can be found in stone, soil and sand) and copper which resulted in bright blue and turquoise glazes.

The next step in the evolution of glazes was the discovery of lead, which was added to glazes in various forms, right up until the 19th century, when people became aware of lead poisoning!

Another important ingredient in early glazes was ash. This was blown through the kiln, forming a coating on the pots.  It is interesting to note that many of these early glazes were probably discovered by chance.

Today the glazing process remains pretty much the same: you mix certain ceramic materials and subject them to heat and various atmospheric conditions to create a glaze.

For many potters, the bible of glazes to refer to is THE GLAZE BOOK by Stephen Murfitt. This is basically a recipe book for achieving different effects by applying additional ingredients to the top layer of glaze.

If you’re interested in taking part in a glazing course at Infinity Clay, drop us a line and if we can get enough people interested, we will get the course organised.

Until next time, happy potting,