Mashad is a city in Iran's far north-eastern region. Mashad rugs have been exported since before 1555, with some rare specimens making their way to museums all over the world. The wool pile used in Persian Rugs are among the best in Iran, and it is usually based on a cotton substrate. The pile is tight and thin, and the wool is silky. The main colours used in the carpets making up a curvilinear pattern with a single central medallion are dark red, blue, and khaki; the corners usually depict floral designs, and floral themes dominate the backdrop. Many of the world's best carpets are created in Iran, and many of Iran's best carpets are manufactured in Mashad (at the Saber studio), demonstrating the importance of Mashad as a carpet-weaving centre. Although designs of any size can be found, the majority of Mashad carpets are very huge.