Normal glass doesn't have the problem of "aging" in the natural
environment. The chemical composition of glass is very stable. In the natural state, the performance of glass is not weakened by sunlight, rain and fog, and it can also resist common acid and alkali erosion. Generally, there are two conditions that affect the life of glass, humid air and high temperature. The chemical reaction caused by long-term storage of glass or humid weather, rainbows, mildew spots/spots, watermarks, mimeographs, paper patterns and other phenomena appear on the glass surface under sunlight, commonly known as glass mold, also known as anti-alkali.