Carpets or rugs made using knots, in the most common method of creating pile carpets; knots are formed by tying yarn around two warp strands to form a knot on the surface of the textile. After each row of knots is created, one or more strands of weft are passed through the warp strands. Then the knots and the weft strands are beaten with a comb securing the knots in place. The number of knots per square inch determines the appearance and texture of the rug.