 Unlike kilim, the back is left ragged, with all the loose ends of the differently-coloured weft threads visible, sometimes several inches long, providing extra thickness and warmth.Also unlike kilim, there are no slits where colours meet, as there is a supplementary or structural weft which supports the coloured pattern weft.Some late Soumaks made by the Kurds are however "weftless", lacking the structural weft support, and the stitches naturally overlap.