Banknote printers have an honest tradition. A specimen note is printed with full craft, overprinted with the word SPECIMEN, and sent out to show what the press can do. Nobody can spend it. Nobody is misled by it. It is simply proof of skill.
Studios have a less honest tradition. Unsolicited concepts appear in portfolios beside commissioned work, with the difference left for the reader to discover.
Most of our concepts exist because no client would have asked for them in that form. They are often the best evidence of what we can do, and they are also not client work. We say which is which, on every page. It costs us nothing, and it means that when we say a project was commissioned, you can believe it.
An engraved banknote, close. Photograph: Victor G, Unsplash.