Carbon fiber reinforced polymer as epoxy, but other thermoset or thermoplastic polymers, such as polyester, vinyl ester, or nylon, are sometimes used. The composite material may contain aramid (e.g. Kevlar, Twaron), ultra-high-molecular-weight polyethylene (UHMWPE), aluminium, or glass fibers in addition to carbon fibers. The properties of the final CFRP product can also be affected by the type of additives introduced to the binding matrix (resin). The most common additive is silica, but other additives such as rubber and carbon nanotubes can be used. The material is also referred to as "graphite-reinforced polymer" or "graphite fiber-reinforced polymer" ("GFRP" is less common, as it clashes with
Unusual types of gramophone records 10 cm or 2.75 and 4 inches) make them unplayable on turntables with automatic return tonearms. In the Soviet Union in the 1930s and 1960s, bootleg copies of banned Western music were individually recorded onto used medical x-ray film and sold on the black market. These were called "ribs" or 'Roentgenizdat'. The first discs by Berliner Gramophone were black, and that has been the standard color for gramophone records in times subsequent. As early as 1899, the Vitaphone Talking Machine Co. made records that were brownish-red in color. The American Record Company produced records made of blue shellac for their