DVD CDs (0.74 µm for DVD versus 1.6 µm for CD), accounting in part for DVD's increased storage capacity. In comparison, Blu-ray Disc, the successor to the DVD format, uses a wavelength of 405 nm (violet), and one dual-layer disc has a 50 GB storage capacity. Read and write speeds for the first DVD drives and players were 1,385 kB/s (1,353 KiB/s); this speed is usually called "1×". More recent models, at 18× or 20×, have 18 or 20 times that speed. Note that for CD drives, 1× means 153.6 kB/s (150 KiB/s), about one-ninth as swift. DVD-Video is a standard
Picture disc many years later. These were deluxe picture discs, priced much higher than ordinary records, and they sold in very small numbers. In the early 1930s the entire record industry was being devastated by a worldwide economic depression and the proliferation of the new medium of radio, which made a wide variety of music available free of charge. Picture discs of all kinds were among the casualties. With the Great Depression and World War II no longer around to interfere with such modest luxuries, the picture disc reemerged in 1946, when Tom Saffardy's Sav-Way Industries began issuing Vogue Records. Vogues were