His first comics story, Le Rhum du Punch, illustrated by his childhood friend Jean-Claude Mézières, was published in 1966 in Pilote magazine.

Christin returned to France the following year to join the faculty of the University of Bordeaux.

That year he again collaborated with Mézières to create the science-fiction series Valérian and Laureline for Pilote.

[citation needed] In addition to the ongoing Valérian, Christin meanwhile wrote several other comics one-shots, including The City That Didn't Exist (La Ville qui n'existe pas), The Black Order Brigade (Les Phalanges de l'ordre noir) and The Hunting Party (Partie de chasse) (all illustrated by Enki Bilal).

Among the many European comics artist he collaborated with were Enki Bilal, Jacques Tardi, Alexis, Raymond Poïvet, Jijé, Annie Goetzinger, Daniel Ceppi, and François Boucq.