After his end exam at the art academy Joost moved into a studio on the Spanjaardshof at the Westeinde in The Hague. Soon enough students came to be taught by Joost. He was a painter that could teach. He had a sense of humor and created a comfortable atmosphere. Some of his students came every week to his studio for twenty years. The studio, by then, was situated in Atelier-2 at the Zwartepad in Voorburg, that he run together with colleague artist Frans Kokshoorn. In Atelier-2 and in his home close to the racecourse Duindigt a lot of important works came to be.