Used to be the King would order more tin or other base metals in the mix -- so the coins would be less gold or silver, or even copper. Nowadays there is no limit to the sovereign's theft by dilution.
About paper money we used to warn of John Law's scheme, and then of the Weimar wheelbarrows, and most recently Mugabe's Billion Dollar Bills. But what, in the end, can match Bernanke's helicopter distrubutions?