Ishfahan has been one of the centres for production of Persian Rugs since the 16th century when several royal factories were established. Weaving in Isfahan flourished in the Safavid era. But the Afghans invaded Iran, ended the Safavid dynasty, and the craft became stagnant. It was only in the 1920s that weaving was again taken seriously by the people of Isfahan. They started again to weave Safavid designs and became one of the most important centres of the Iranian rug weaving industry. Isfahani carpets today are among the most wanted in world markets, having many customers in western countries. The rugs and carpets usually have ivory backgrounds with blue, rose, and indigo motifs. Rugs and carpets often have very symmetrical and balanced designs. They usually have a single medallion that is surrounded with vines and palmettos and are of excellent quality.