Many people want to know what the glaze is. Glazing is a technique that requires:
Color Glazes are a type of glass that are specially made to stick onto pots and other ceramic surfaces. When molten, this specialized glass is stiffer than glass that is poured or blown is. This is important, as otherwise, the glaze would run off the vertical surfaces of the pots when brought up to temperature in the kiln.
Clay glaze colors come in a huge array of colors, the result of minerals and inorganic compounds. The most commonly used colorants are iron oxides, cobalt oxide, chromium oxide, copper oxide, and copper carbonate. A glaze's color may also be affected by the firing process. If the atmosphere in the kiln has plenty of oxygen, it is called an oxidation firing. If the atmosphere has very little oxygen, it is called a reduction firing. The amount of oxygen present in the kiln can drastically change a glaze's color. For example, a basic glaze using copper carbonate to color it will be turquoise if fired in an oxidation atmosphere, or bright red if fired in a reduction atmosphere. Most glazes are semitranslucent, except blush transparent glaze and laurel green color glaze.
More about Painting and Glazing can be found on this link: Color glazes on Wikipedia