When Penguin Modern Classics decided to bring back its Crime and Espionage series, one design feature was surely inevitable. For Penguin readers, crime is synonymous with green. The colour has been a staple of the publisher’s Crime jackets for the best part of a century, and the new editions pay tribute to this design signature.

“The shade of green used on Penguin’s crime novels has changed over the years,” explains Matt Young, head of design at Penguin’s Illustrated Books, who worked on the new series. “When Penguin Books launched with ten colour-coded books in 1935, ‘Crime’ was a deep green colour, which to me always suggested cosy British countryside murders. In 1961 Romek Marber overhauled the Crime livery, introducing bold illustrated covers, and changing the hue to a much more vibrant and altogether more toxic green, which felt like a perfect match for the grittier crime novels being published from the 60s onwards.

“When choosing our exact shade of green for our new covers we did print tests of a variety of different hues, including comparing spot colours versus CMYK printing, and what we’ve ended up with is very similar to the green of the 1960s. It offers good contrast with both black and white text, and pairs delightfully with the graphic black and white illustrations.”

Drawing on a mix of existing Penguin titles and others that are new to the publisher, the first tranche of ten books, which includes authors such as John le Carré and Len Deighton, has just been released. When pushed to pick a favourite design so far, Young opts for Georges Simenon’s Maigret and the Headless Corpse. It shows the cork of a bottle snapped jaggedly in two – a nice homage to the ‘bottle green’ shade seen on the old Penguin covers, whether intentional or not. “It was the very first one I designed, and it kicked off the visual language for the whole series.”

“Our aim was to create covers which are bold, graphic, and unmistakable,” he explains. “It’s important to note that these are modern classics, mostly from the 1930s, 40s, 50s, and 60s – they’re not brand-new 2023 crime fiction – so there’s a deliberate nod to the past, and in particular to Penguin’s rich design history and the illustrated covers designed by Romek Marber and others in the 1960s.”

“The consistent ingredients are the colour palette and the typography, and within that framework the covers can accommodate photography, collage or illustration. The layout is flexible – the title, author, quote, and Penguin logo can be positioned anywhere on the cover, working within or around the imagery. There’s a very confident pared-back look to a lot of these designs which is unlike anything else you’ll find in the crime section in bookshops.”

Nonetheless, the visual language gels seamlessly with the genre, for instance the running thread of collage and newspapers, which subtly evoke anonymous notes, stamps suggesting secret correspondence, and blotchy textures that resemble fingerprints.

The covers were designed to look as though they came together “effortlessly”, Young says. “We have a theory, half-jokingly, that the covers should look like they were executed in 30 minutes or less. Sometimes they really were pieced together that quickly, and other times a great deal of effort has gone into making them look effortless.

“The cover for Journey Into Fear was probably the best example of this – the story is about an assassin and their target both on a ship sailing across the Mediterranean, and I wanted to convey the sense of complete isolation that comes with being out at sea, with nowhere to run or hide,” he tells us. “I knew I wanted the cover to show a ship sailing off into the distance, but getting the tone just right took a lot of experimentation.”

The era in which the books were first published fed into the lettering on the covers. “Most of these books were written around the middle of the 20^th century, and it’s likely that every single one of these authors would have bashed out their manuscript on a good old-fashioned manual typewriter. They certainly wouldn’t have been typing them out in Microsoft Word,” Young says. “So using a typewriter face felt like the right way to go – it has an authenticity that chimes with these books and the time they were written.

“We did, briefly, consider dialling the authenticity up to eleven by sourcing an appropriate typewriter for each individual novel. For example, for George Simenon’s books we’d find a Belgian 1950s typewriter; for Edogawa Rampo’s stories we’d type out the title on a Japanese typewriter from the 1940s; and for John le Carré it’d be a British 1960s model.”

In the end, the team decided to use FF Elementa, “which isn’t specific to any time or place, but feels like the quintessential typewriter face,” he explains. “Indeed, the designer, Mindaugas Strockis, has said that the letterforms ‘came from a dream of how the perfect typewriter should be’.”

Penguin Modern Classics Crime and Espionage series is out now; penguin.co.uk