Franz and Felix Hoffmann, in 1919, return safe and sound from the First World War. Jointly with their father, the master builder Franz Hoffmann, they set up the general partnership corporation Franz Hoffmann & Söhne. Son Franz is a qualified merchant, Felix an architect, so the brothers nicely complement each other in their work. Franz assumes the responsibility for the commercial interests, Felix as a technician takes care of the buildings and the equipment. With all their forces, the two devote themselves to the "Chalk Business". Father and sons succeed in signing a supply and cooperation contract with the English company Reckitt & Colman, then the no. 1 manufacturer of polishing agents in the world. The resulting business relations have continued until today. Furthermore, the brothers open up the company’s way into the rubber industry. Skill, hard work and also courage are the elements of the successful approach that enables Franz and Felix Hoffmann to develop and consolidate the siliceous earth business.