expanded to include non-flexi-disc novelty releases from musicians such as Chris Sievey. Chocolate records about three inches in diameter, and small players made for them, were marketed as a novelty in Europe in 1903–1904. After a record or its amusement power wore out, it could be eaten. In 1973, the Kingdom of Bhutan issued several unusual postage stamps that are playable miniature phonograph records. These thin plastic single-sided adhesive-backed 33 RPM discs feature folk music and tourism information. Not very practical for actual postal use and rarely seen canceled, they were designed as revenue-generating novelties and were initially scorned as such by most stamp collectors. Their small diameters (approximately 7 and 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'. Unusual appearance Colored records The first discs by Berliner Gramophone were black, and that has been the standard color for gramophone records ever since. But 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 flagship label, although pressings for client labels were made in standard black. Unusual colors, and even multi-colored shellac first appeared in the 1910s on such labels as Vocalion Records. In the 1920s, several companies made records of various shades of brown, including Perfect Records and Grey Gull Records. When RCA Victor launched the 7-inch 45 rpm record, they initially had eight musical classifications (pop, country, blues, classical, children's, etc.) each with not only its own uniquely colored label but with a corresponding color vinyl. According to experts at the Sarnoff Center in Princeton, New Jersey, the cost of maintaining eight vinyl colors became too high, but the different colored labels were continued, at least for popular music (black) and classical (red, as in "Red Seal"). In October 1945, RCA Victor put on the market its first "non-breakable" phonograph records. Made of a ruby-red, translucent vinyl resin plastic, they cost twice as much ($2 per disc) as the 12-inch Victor Red Seal. In the 1960s, a distinction was made in label colors of promotional copies of 45 RPM records as well, with pop music being issued