Glass Characteristics

Glass COE

• COE stands for Coefficient of Expansion

• COE refers to how much a glass expands or contracts with changes in temperature.

• To prevent cracking or breaking, use pieces with the same COE.

• Never fuse together differing COE glass because they expand and contract at different rates. Breakage will result either in the kiln or several years later on your bookshelf!

ONLY use COE 96 glass in the glass studio | NO STAINED GLASS ALLOWED

• Spectrum or Oceanside COE 96 glass is recommended.

• Scraps of glass other than COE 96 should be taken home.

• Avoid Wissmach glass as it is NOT compatible with other COE 96 glass.

• Optical Properties of Glass

• Opaque: light does not go through the glass

• Transparent: glass is clear and light goes through

• Translucent: light partially goes through the glass but objects on other side are not clear

• Opalescent:  term for clear or colored glass with a milky white opaque or translucent effect

• Wispy: streaked glass made up of several colors

• Texture: rough on one side and smooth on the other

• Dichroic:  glass that displays multiple different colors depending on lighting conditions

• Iridized: glass with thin layer of metallic crystal, creating jewel-like colors in reflected light.

Two Layer Rule

Fully fused glass will always want to be about 1/4 inch (6mm) thick.