A set of plates is a type of ARMOR that consists of overlapping metal plates, usually made of steel, which are connected to form a protective covering. It was used in the Middle Ages and Renaissance periods to protect soldiers from weapons such as swords and arrows. The plates were often decorated with intricate designs and symbols, and could be tailored to fit the individual wearer. The use of plate ARMOR declined in the 17th century due to the development of firearms, which rendered it ineffective.