While any pile rugs will upgrade the appearance of any room, tribal rugs with their unique colors and designs, lend a special warmth that cannot be achieved otherwise. The tribal rugs is essentially a one-off work of tribal art usually created by nomadic or semi-nomadic people living in small villages or on the open plains where the raw materials for the rugs come from their own animals from or bought from shops along their routes of travel. It can take several months for one person to make even a small prayer rug, and larger carpets may require the daily work of several persons for more than a year. The value of the tribal rug is therefore directly related to the time and effort made to create it. The quality of the materials and complexity of design affect the time required to create these carpets and these factors also affect the value. An important factor in determining a carpets value is the source of the carpet- i.e.: where was it made and by what tribal group? Carpets of generally similar design, size, materials and workmanship can be made in widely different geographical areas.