What is eisenglass definition?

Eisenglass is a type of transparent, flexible sheet material made from the collagen-rich skin of a fish, particularly the Atlantic cod. It is often used in boats and other water vehicles to provide protection from wind and water while still allowing for visibility. Eisenglass is a more durable and scratch-resistant alternative to plastic window materials, and can also resist damage from UV radiation. The name "eisenglass" is derived from the German words for "iron" and "glass," as it was originally used as a window material for horse-drawn carriages in the 19th century.