Source Adventurer’s Armory
Sneaks and thieves know the value of a good disguise. The ability to remove that disguise in a hurry, thus revealing the next layer of disguise, is nearly as valuable. Tear-away clothing is generally loose fitting and long to allow another layer of clothing to be worn underneath. The seams and catches on this clothing are designed to break easily, making it a simple matter (a standard action) to remove these items and walk away with none the wiser.