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 the discs as a medium for propaganda. Adolf Hitler and British fascist Oswald Mosley were each featured on their own special picture discs. Most of these records were made of a simple sheet of fairly thin printed cardboard with a very thin plastic coating and their audio quality was substandard. Some were more sturdy and well-made and they equaled or actually surpassed the audio quality of ordinary records, which were still made of a gritty shellac compound that introduced a lot of background noise. In 1933, RCA Victor in the U.S. issued a few typical cardboard-based picture records but was