Tarahumara women weave two different kinds of blankets. The one on the left—rectangular in shape with fringes on either end—is a frazada. The one on the right—nearly square, with corner tassels instead of fringes—is a tiruta. Both types of blankets are used as bed coverings, outer garments, and makeshift bags. In the past, tirutas were more common than frazadas throughout the Tarahumara area, but today they are woven only in a few Tarahumara communities. Although this shift in popularity is well documented in photographs and research reports, no one has yet been able to provide a good explanation for why it occurred.