Lifetime expectancy of the various carriers plays the predominant role in this kind of thinking. Even in this rather optimistic scenario, the transmission of the contents of such carriers over a millennium implies the necessity of 20 generations of subsequent preservation or master copies. Though technically possible in the form of metal matrices, this possibility has never succeeded on a large scale because of its enormous costs. There are few examples where metal masters, mainly of the LP format, have been produced just for preservation purposes. The BBC did so in their earlier days, political events of special importance in the former communist countries have been preserved in this way, sometimes also most valuable research materials like historical holdings of the St. Petersburg Phonogrammarchiv.
Durable carriers are also available in parts of the digital world.
With the advent of digital storage techniques, however, the situation has, in principle, changed radically. In the digital domain it is possible to copy information without any loss from generation to generation. Professional digital formats have been envisaged, and accepted as an universal standard, by the late eighties or early nineties. Similar thoughts may have lent wings to our colleagues in the video archives. The market, however, developed differently.