The term “Significant Side” is used if there is a necessity to distinguish which side of a glass pane is “up” or “down” or “front” or “back” while processing the glass pane. Typical examples are:

• When producing flat glass, one side is floating on the tin bath, the other is exposed to the gas fire heating the chamber.
• If the glass is coated (a thin metallic layer is applied), it is essential to know which side is coated
• Glass having patterns or other surface treatments