Geldesign.

He snatched a piece of paper from Owlswick's box, and pulled out a pencil. 'Look,' he said, 'you start with...'

What?

'Richness,' he told himself, aloud, 'richness and solidity, like the front of the bank. Lots of ornate scrolling, which is hard to copy. A ... panorama, a cityscape ... Yes! Ankh-Morpork, it's all about the city! Vetinari's head, because they'll expect that, and a great big One so they get the message. Oh, the coat of arms, we must have that. And down here' — the pencil scribbled fast — 'a space for the chairman's signature, pardon me, I mean paw print. On the back ... well, we are talking fine detail, Owlswick. Some god would give us a bit of gravitas. One of the jollier ones. What's the name of that god with the three-pronged fork? One like him, anyway. Fine lines, Owlswick, that's what we want. Oh, and a boat. I like boats. Tell 'em it's worth a dollar again, too. Um ... oh yes, mystic stuff doesn't hurt, people'll believe in any damn thing if it sounds old and mysterious. "Doth not a penny to the widow outshine the unconquered sun?"'

'What does that mean?'

'I haven't the foggiest idea,' said Moist. 'I just made it up.'

Terry Pratchett: Making Money