Spelling bee word again.
ABRASH

The word used to describe the variations in color found within a single color in an Oriental carpet. Abrash is
commonly seen in tribal nomadic rugs and in reproductions of them. Mild Abrash is caused by variations in yarn
diameter native to nomadic dyeing and yarn spinning. Heavy Abrash is caused by the change over to a new dye batch.
Generally Abrash is desirable in tribal carpets and undesirable in urban carpets.

I also got a dozen site where Abrash is somebody's name.