Baluch nomads are groups of different races who roam between Persia and Western Afghanistan. The Baluch weave wool carpets which are very durable, of high quality, with a dense and tight weave. Their warp is wool, and sometimes they also use goat's wool. In modern carpets they also use cotton warp. Many carpets have decorative Kilims on both ends of their width, which makes the carpets more durable and protects against wear. The thin rails of the carpets are often goat wool. They use dark red, blue, brown and black herbal colors. The designs are geometric and often represent in a variety of forms the tree of life, a symbolic scene used often in prayer carpets. The Baluch carpets that were dealt in the city of Iran, Mashad, are called Mashad-Baluch, while others sold in the city of Herat in Afghanistan, are known as Herat-Baluch.