Artists working in the stamp art medium often employ fixed-line perforators as part of the creation process. Most functional and sought-after of these machines are cast-iron, pedal-operated devices manufactured beginning in the 1880s by bindery equipment makers like F.P Rosback Co. and Latham Machinery Co. Rosback also produced table-top perforators, but surviving models are exceedingly rare. Other methods for perforating paper to resemble stamp sheets have generally proven unsatisfactory. Such alternative methods used include using sewing machines, sewing pounces, leather punches, modified veterinary needles, and speciality scissors. Some owners of pedal-operated or motorized perforators sell pre-perforated paper and offer perforating services for a fee.