This ordinary appearing robe cannot be detected by magical means. 

When it is put on, however, the wearer will detect a dweomer and know that the garment has very special properties. 

A robe of blending enables its wearer to appear to be part of a rock wall, a plant, a creature of another sort—whatever is appropriate. The coloration, form, and even odor are produced by the robe, although it will not make its wearer appear to be more than twice/one-half normal height, and it does not empower language/noise capabilities—either understanding or imitating. 

(In situations where several different forms are appropriate, the wearer is obliged to state which form he wishes the robe to camouflage him or her as.) 

Creatures with Exceptional (15+) or better Intelligence have a 1% per Intelligence point chance of detecting something amiss when they are within 3" of a robe of blending, and those creatures with Low Intelligence (5+) or better and 10 or more levels of experience or hit dice have a 1% per level or hit die chance of likewise noting something unusual about a robe-wearing character. (The latter is cumulative with the former chance for detection, so an 18 Intelligence magic-user of 12th level has a 30% chance—18% + 12%—of noting something amiss.) 

There must be an initial check per eligible creature, and successive checks should be made each turn thereafter, if the same creatures are within the 3" range. 

All creatures acquainted with and friendly to the wearer will see him or her normally.