Isfahan rugs are knotted on either silk or cotton foundations, with up to 1.000.000 Persian knots/sqm, using exceptionally good quality (referred to as kork wool in Iran) wool for the pile, which is normally clipped quite low. At the beginning of the renewal of Isfahan as the carpet center of high-quality rugs, most rugs used traditional motifs inspired by the architectural motifs and tiles that decorated the historical buildings of this great city. Designers were further inspired by the poets of Persia (Rumi, Hafez, Attar), nature, and religious-spiritual intimations that are deeply ingrained in the culture.