Glaze is a coating that goes over a ceramic piece. Mainly used for decorative purposes, glazing is done after the pot has been fired in the kiln. They are a mixture of different powered minerals and metal oxides and these mixtures will make hundreds of differents of colors. There are different ways to glaze a pot; you can paint with a paint brush, dip it in to the glaze, or spray the glaze (many of these techniques can be seen on the showcase page). There are two different types of glaze that are used. The first layer of glaze is called the underglaze, a common type of underglaze is the blue and white porcelain pottery. After the potter has put on the underglaze it is put back into the kiln. Then the over glaze is put on to the pottery, and put into the kiln for the final time. After the over glaze the pot comes out of the kiln with a shiny new look.

When glazing, you are never sure how your pot will come out out of the kiln. The extreme heat from the kiln causes the minerals and the oxides to turn different colors and mix with eachother. The glazing on the pot may come out of the kiln looking nothing like it when it came in.

Here are a few recipes:

Opaque Gloss Crackle
Gertsley Borate-41.9%
Potash Feldspar-32.4%
Pemco Frit #625 or Ferro # 3289-14.9%
Flint-10.8%
For Blue, add cobalt carbonate-1/2% to 1%
For Green, add copper carbonate-3% to 6%

Copper Red
Gertsley borate-8%
Whiting-15%
Nepheline syenite-13%
EPK-9%
Flint-30%
G200-25%
Tin oxide-2%
Copper carbonate-1.5%