The team's cartooning technique – partly inherited but soon individualised – was an animated, breezy, ultra-modern one. Eventually, it became known as 'le style atome'. This moniker derived from the 1958 Brussels World's Fair, whose signature was a sculpture called 'the Atomium'. An outsized icon of Populuxe design, this seemed to match the sparky visual spirit of post-War Spirou. Certainly it paralleled the artists' angular shapes, their streamlined drawings and a use of bright, sharp colours. Graphically much brasher than Hergé's ligne claire, le style atome gave a nod to '50s and '60s US culture. It featured rounder speech bubbles instead of rectangles and privileged short, spunky dialogue over declamations.
Spirou's energetic art is now known as "the Marcinelle school" or "the school of Charleroi". Both terms refer to the site of the Dupuis' printing firm. But those artists who worked with Jijé had a different name for it. They called the work gros nez – or "big nose" – comedy.
The flipside of Marcinelle art was found in the pages of Tintin. A vehicle for Hergé's hero, this weekly was the laboratory of a rival "Brussels' school". Just as Marcinelle art reflected Jijé’s temperament, the Tintin employees operated in Hergé's shadow. Their highly polished work was required to resemble his and, in their atelier, an artist wore his suit and tie. He would labour to produce pristine pages, with refined lines underscored by un-shaded colour.