thongdrels are composed of several layers, mostly of silk. these begin with a backing, then the image itself, made up of appliqué pieces sewn to a background. finally there is a yellow drape that covers and protects it when not on display. thongdrels are stored rolled up. thongdrels are displayed once a year as the highlight of the tsechu festival of a district or "dzongkhag" (although not every district has a thongdrel). typically they are displayed on the last day of the tsechu. the painting is not allowed to be struck by the direct rays of the sun, thus it may be unfurled at around 3:00 in the morning and rolled back up by 7:30 am.