Sometimes when Oriental or Chinese carpets are cleaned, white yarn ends become visible. These strings are from a break in the warp during weaving and the broken ends of yarn are tied together or when the weaver has come to the end of a package of warp yarn and must tie a new package of yarn onto the end of the warp thread. These ends become visible in several ways: the level of the nap wears down; the cotton strings lose dye more readily than the wool when cleaned; and removal of an overall layer of soil which has in effect hidden the white cotton knots.