Alchemical Silver
A complex process involving metallurgy and alchemy can bond silver to a weapon made of steel so that it bypasses the damage reduction of creatures such as lycanthropes.

On a successful attack with a silvered slashing or piercing weapon, the wielder takes a –1 penalty on the damage roll (with a minimum of 1 point of damage). The alchemical silvering process can't be applied to nonmetal items, and it doesn't work on rare metals such as adamantine, cold iron, and mithral.

Alchemical silver has 10 hit points per inch of thickness and hardness 8.

Type of Alchemical Silver Item Item Price Modifier
Ammunition +2 gp per item
Light weapon +20 gp
One-handed weapon, or one head of a double weapon +90 gp
Two-handed weapon, or both heads of a double weapon +180 gp