Is Fiberglass Really Glass?

A substance called fiberglass is used today for a whole range of things — boats, car bodies, skateboards, curtains, even yo-yos. You may have wondered why it's called fiberglass, for it surely doesn't look much like glass.

But fiberglass is made from the same substances as ordinary glass. The glass is heated, and the molten material is pulled into thin threads, which can then be woven together to make fiberglass fabrics.

Fiberglass threads are often used to reinforce plastics, making them stronger without making them heavier. This fiberglass-reinforced plastic is what many people call "fiberglass."

The name fiberglass was originally a brand name, Fiberglas, and could be used only by the company that first made it. But in the United States today, anybody who manufactures glass fiber can call it fiberglass.