Pirot kilim rugs refers to a variety of flat tapestry-woven rugs traditionally produced in Pirot, a town in southeastern Serbia. Pirot kilims with some 122 ornaments and 96 different types have been protected by geographical indication in 2002. Pirot was once the most important rug-making centre in the Balkans, located on the historical main highway which linked central Europe with Constantinople.
Soumak is a tapestry technique of weaving strong and decorative textiles used as rugs and domestic bags. 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 on 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 coloured weft threads over and under the warp threads, adding strength and embroidery-like pattern.
Soumak is also spelled Soumakh, Sumak, Sumac, or Soumac.