What is glaze?
The glass-like coating that covers the surface of ceramics is called glaze. It is hard like glass and has excellent acid and alkali resistance.
Applying glaze is called glazing, and this increases the hardness of the pottery and also eliminates water permeability, preventing water leaks and oil stains.
In addition to these practical purposes, glazing also serves a decorative role through color and luster.
The origin of glaze was discovered by chance when firewood ash was sprinkled onto a pottery in a kiln, which melted at high temperatures and became glassy.
There are many different types of glazes, but they can be classified into three types depending on their basic ingredients: ash glaze, feldspar glaze, and lead glaze.
Metals such as iron and copper are added to these to create glazes of various colors. The glaze applied to the fabric does not retain its color.
The small amount of metal contained in the glaze and fabric undergoes various chemical changes due to the flames in the kiln, resulting in color.
The flame is determined by the air inside the kiln, that is, the amount of oxygen.
If the fabric or glaze contains iron, the color will be blue if it is a reducing flame with a low supply of oxygen, or yellow if it is an oxidizing flame with a high supply of oxygen.
Even if the same glaze is used, the way the color develops differs depending on various conditions such as subtle differences in the ingredients of the glaze and fabric, amount of glaze applied, firing method, fuel, etc. This profound fact has made it possible to create a variety of expressions in today's pottery. You can say that.