The Tribal or Nomadic Rugs are woven by the people that move from place to place depending on the season. They move to the mountain pastures and higher grounds in the summer and to the lower lands in the winter. The article in The Persian Knot has some wonderful photos of the people and the environment they live in.
The weaving is considered a practical way of providing the material that they can use. Most of the rugs are functional pieces such as small rugs for the tents, horse blankets, saddlebags, and grain sacks. The material most likely is all wool since that is what is available to them. The dyes used to color the wool are all from the vegetable and plants that they gather. The designs in the rugs tend to be very simple and often the animal forms such as birds, sheep, and horses are found as part of the design.