Linothorax

While most people think of greek hoplites clad in bronze armor, this became far less common then most think. The expense of bronze armor, the time and effort to make the armor, the weight of the armor and the stifling heat of wearing the armor in a warmer climate all worked against it. Instead linothorax armor was developed and widely used.

From wikipedia:
The linothorax appears to have been used in place of the bronze “bell cuirass” as the popular choice of armour for Greek hoplites, starting perhaps around the late seventh century and early sixth century B.C. This could have been due to the lower price, lesser weight, and cooler material. Its high point in vase paintings, sculptural reliefs and artistic depictions corresponds with the time of the Persian Wars. By the time of the Peloponnesian War it was still used, and continued to seemingly flourish well into the Hellenistic Period... 

In Xenophon's Anabasis Xenophon has to scour the 10,000+ troops to find enough bronze curiasses to give to his 300 cavalry...because the majority of those who had armor, wore linothorax.

Linothorax was formed by layering sheets of linen (from 10-20) and gluing them together. The armor itself becomes flexible when warm due to body heat of the wearer as well as heat of the day. The end result? A tough and lighter body armor that resisted sword hacks, spears and arrows.

Recently a team at the University of Wisconsin-Green Bay researched, manufactured linothorax and then tested its resilience to weapons.  Take a look at the results:

In addition the project team at UWGB came up with a neat infograhpic poster all about linothorax, their tests and its usage

Linothorax in Heroes & Other Worlds
As an armor , in game terms, linothorax would be comparable to leather as AR-2/DX-1, cost 75 coins.  You would expect to see linothorax worn in areas that lacked large cattle herds or enough raw metal to supply  metal for armor. In addition warmer/Mediterranean climates, warriors would forgo metal armors in favor of a linothorax style of armor. In fantasy terms, Elves would also favor a linothorax style of armor so as not to use animal hides for body armor. Hobgoblins might also favor it as it is light but strong allowing them to remain quick in combat but protected-and as the smartest of the goblinoids, the would understand the cheaper, lighter, flexible yet strong protection provided by linothorax.