Although this item was created by dragons and is still crafted almost exclusively by them, it can be used by intelligent creatures of any race or class. It takes the form of a small sheet of the thinnest, most filmy material imaginable. It's effectively invisible unless a creature is actively looking for it, and even then, the chance of noticing it is only 60%.
To be effective, the gauze needs to be draped around the top of a doorway or portal so that anyone trying to pass through the portal must brush the gauze. The gauze immediately makes any invisible creature that touches it visible again. In addition, the creature who touched the gauze is totally convinced he or she is still invisible, and unwilling to believe anyone who tries to claim otherwise.
Gauze of appearance also dissipates any illusions that pass through it, and strips away the effects of minor spells like change self. Even the effects of a hat of disguise or a similar item is reversed by the gauze.
Dragons frequently drape lengths of gauze around their treasure hoards. Although they can usually detect invisible intruders, any animal guards they may be using might not be so lucky.