Comparison of high definition optical disc formats Blu-ray disc players since the end of the format war. Blu-ray Disc has a higher maximum disc capacity than HD DVD (50 GB vs. 30 GB for a double layered disc). In September 2007 the DVD Forum approved a preliminary specification for the triple-layer 51GB HD DVD (ROM only) disc though Toshiba never stated whether it was compatible with existing HD DVD players. In September 2006 TDK announced a prototype Blu-ray Disc with a capacity of 200GB. TDK was also the first to develop a Blu-ray prototype with a capacity of 100GB in May 2005. In October 2007 Hitachi developed
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