Jacopo Prisco , CNN Written by

The British Museum explores the history and design of communist banknotes in its latest exhibition, open this week. But the show's title, "The Currency of Communism," is -- in theory -- a contradiction in terms, according to curator Thomas Hockenhull.

"Under full communism, or Marxist theory, there should be no money," he said in a phone interview.

"It's a social construct, therefore it should not exist -- and yet we have the material evidence in front of us, currencies from all these countries that never succeed in eliminating money from their economies."

Since the October Revolution of 1917, more than 20 countries have adopted some form of communism -- so why did none of them abolish money?

"The answer is that it was too difficult: It's impossible to interact with capitalist states without some form of monetary exchange," said Hockenhull.

Instead of eliminating money altogether, which may have caused economic chaos, communist states pursued a different approach: "The currency was symbolically devalued, to give citizens an indication that they should not value monetary wealth, but other things such as social interaction and access to art and culture."

This move brought about a transformation. Stripped of value, money instead carried a message: "It became an organ of state propaganda, a visual representation of the state's aspirations, and easily the most circulated one," said Hockenhull.

While banknotes' designs were heavy with classic socialist symbols such as workers, foundries and large infrastructure projects, more specific messages were relayed through posters and public ads, which also form part of the British Museum's exhibition.

"Saving Bit by Bit, We'll (Be Able To) Buy," USSR, 1955. Credit: Courtesy The British Museum

One poster from the USSR shows a family gathered around a piano, along with the message that saving money "bit by bit" was the only way to buy an expensive item, as there was virtually no access to consumer credit at the time.

The iconography can be taken to comical extremes, such as a Somalian banknote -- designed to empower women -- which shows a woman holding a shovel, a gun and a baby simultaneously. But for Hockenhull, the items on display share one common trait: "The images on the notes are startlingly beautiful," he said.

"They're very aspirational, they show the kind of idealized state that the social government wanted to build."