Gossamer (3.5e Equipment)
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This soft fabric is thinner than any other natural fabric, but also amazingly resilient. It is also fire resistant, but still gets hot when burned. When made into tight-fitting clothing, it provides a +1 armor bonus as though it were armor, but does not stack with other armor bonuses. These clothes, while tight, are quite comfortable. Gossamer often appears in pastel colors and is rare and valuable. A gossamer suit is usually worn underneath normal clothing or armor. However, if armor is worn over a suit of gossamer clothes, this bonus to the wearer's armor class is lost. Equipment, such as satchels and backpacks lined with gossamer can protect contents from burning in flames.
When available, gossamer is purchased by the square yard in rolls, or by custom order from tailors as a finished product. A medium creature requires 4 square yards of gossamer to make a full suit. That number is doubled for large creatures, and doubled again for every size after. Small creatures only need half the amount of medium creatures (2 yards) and the number is halved again every size smaller.
Gossamer costs 100 gp per square yard.
Gossamer has 5 hit points per inch of thickness and hardness 5.
 Origins of Gossamer
Gossamer is a natural material spun together from several sources, most of which are kept as a trade secret by its manufacturers. However, it is known that several silks are used in its production, as well as a fiber from a specific grass that is both delicate and strong. It is believed that the material undergo an alchemical process that binds them and alters their nature.
 Introducing Gossamer into Your Campaign
Gossamer alone isn't a game breaker with its +1 armor bonus and its relative cost compared to other light armors. Though at less than the cost of a ring of protection, and non-magical, it is a good deal for mages who have yet to get a good robe or other magic vestment. Speaking of magic vestment, gossamer provides an excellent starting point at crafting a permanent magic vestment. Such things can be sold in stores, but are costly.