"Unlike yarn rinsed in city water, river-washed yarn has a vivid, but not harsh, brightness to its colors and a recognizable depth."

The first step in dyeing yarn involves boiling the wool in large pots containing the skins of walnuts and zaj (a mineral salt). Clay pots are preferred to commercial vats. The resulting natural chemical reaction cleans the wool and activates the molecules to accept future dyes without destroying the lanolin.

The best dyes are taken from flowers, leaves, roots, and other naturally occurring substances found in the Iranian countryside. Again, as in the wool, the geographic area from which the dye materials are gathered and their quality will have a direct impact upon the visual appearance of the carpet and its colors.