Optical disc composed of a phase change material, most often AgInSbTe, an alloy of silver, indium, antimony, and tellurium. Optical discs are most commonly used for storing music (e.g. for use in a CD player), video (e.g. for use in a Blu-ray player), or data and programs for personal computers (PC). The Optical Storage Technology Association (OSTA) promotes standardized optical storage formats. Although optical discs are more durable than earlier audio-visual and data storage formats, they are susceptible to environmental and daily-use damage. Libraries and archives enact optical media preservation procedures to ensure continued usability in the computer's optical disc drive or
Picture disc from the late 1940s through the 1950s. Their most popular and well-known issues resembled Vogue records in their general style of illustration and use of high-quality materials, but they were only 7 inches in diameter, had no reinforcing core disc, and sold for a much lower price. Other companies such as Voco also made picture discs for children. Red Raven Movie Records, introduced in 1956, were a very unusual type of children's picture disc. They featured a sequence of sixteen interwoven animation frames arrayed around the center and were to be played at 78 rpm on a turntable with a