In a world of contactless payment and online transfers, it sometimes feels as if “real” money – tangible, rustling cash – is disappearing altogether. But this isn't the case in Hollywood, where massive stacks of paper banknotes remain one of the most enduring movie symbols of wealth and excess. No one buys drugs or pays their hitman via credit card. The trope of the “briefcase full of cash” has cropped up so often, it’s now played as a joke: in the opening credits of horror comedy Zombieland, a man desperately throws a briefcase of money into the air as he flees from two zombies. Perhaps most striking of all are scenes in which huge amounts of money are treated with cavalier disrespect: think of Heath Ledger’s Joker setting fire to a mountain of cash in The Dark Knight, or the TV series Breaking Bad, which memorably featured a scene in which characters recline on a huge pile of notes – $52,372,000 worth, if this mathematically inclined fan’s calculation is to be believed. But what most people don’t think about when watching the on-screen clips of huge amounts of money, is that it’s actually pretty rare to see real banknotes on screen – and the world of fake movie cash is governed by strict laws.