Inside the secrets of Caran d'Ache, the brand that made pencils a gold mine. Located not far from Geneva (Switzerland), in Thônex, the famous house specializing in illuminated stationery since 1915.

A giant colored pencil stands in front of the entrance. “Don't look for it, it's graphite, which we cook at 1,000°C to make mines,” explains, amused, Éric Vitus, the director of the fine arts section.