The name of a weaver or workshop woven into a rug, either in a small framed box (a cartouche) or directly into the border stripes. It works as a maker's mark that ties the rug to that workshop's standards; signed pieces from famous workshops sell for more and are sought by collectors, and a rug sold under a workshop's signature must truly come from that workshop. Not every workshop rug is signed, and a workshop can stop using its signature. Isfahan rugs and newer Qum rugs usually carry one, while most Nain rugs, silk-foundation Yomut Turkoman rugs and many older Qum rugs do not.