Tabriz rug weavers have great skill, and are aided by a hook-like implement, which they use instead of the fingers for tying knots. The warps and wefts are cotton, the pile wool and with highlights of silk that can be found in the finest pieces. The colours of the finer carpets are delicate and refined. The coarsest qualities are brightly coloured and rarely exported. A wide variety of designs are seen: copies of classical designs, re-workings of old motifs, and pictorial or figurative treatments.