Soumak (also spelled Soumakh or Soumac) is a tapestry technique of weaving strong and decorative textiles used as rugs and domestic bags. Baks used for bedding are known as Soumak Mafrash. Soumak is a type of flat weave, somewhat resembling but stronger and thicker than kilim, with a smooth front face and a ragged back, where kilim is smooth both sides. Soumak lacks the slits characteristic of kilim, as it is usually woven with supplementary weft threads as continuous supports. The technique involves wrapping colored weft threads over and under the warp threads, adding strength and embroidery-like pattern.