Plastic was invented in the 19th century and was originally used to replace common materials such as ivory, rubber, and shellac. They were first used commercially in 1947 but remained relatively expensive until the early 1950s when high-density polyethylene was introduced. They quickly became popular with both manufacturers and customers because of their lightweight nature, relatively low production, and transportation costs compared to glass bottles. However, the biggest advantage plastic bottles have over their glass counterparts is their superior resistance to breakage, in both production and transportation. Except for wine and beer, the food industry has almost completely replaced glass bottles with plastic bottles.