What is glaze?
Q: What is glaze?
A: Glaze is a layer or coating used on pottery or ceramics, also known as vitreous enamel or porcelain enamel. It is made by fusing powdered glass onto ceramics and firing it at high temperatures.
Q: What are the different types of glaze?
A: There are many different types of glaze, some are used for decoration and some are used to make pottery watertight so it can hold liquids. Glazes may also enhance an underlying design or texture.
Q: What materials does ceramic glaze consist of?
A: Ceramic glaze raw materials generally include silica, which forms glass when fired, metal oxides such as sodium, potassium and calcium which act as a "flux" to lower the melting temperature, alumina which stiffens the molten glaze to prevent it from running off the piece, iron oxide for colouring, copper carbonate or cobalt carbonate for further colouring and tin oxide or zirconium oxide to make the glaze opaque.
Q: How hot must ceramic be fired in order to fuse the powdered glass onto it?
A: Ceramic must be fired between 750 and 850 °C (1,380 and 1,560 °F) in order for the powder to melt and flow before hardening into a smooth lasting vitreous coating on metal, glass or ceramics.
Q: What is one example of how glazing has been used in building materials?
A: The Iron Pagoda built in 1049 in Kaifeng China is an example of how glazing has been used in building materials as it was constructed with bricks that were covered with a layer of glazed material.
Q: What purpose does glazing serve?
A: Glazing serves multiple purposes including colouring items, decorating them strengthening them and waterproofing them so they can hold liquids without leaking.
