The Formative Years and the Grand Tour The studio of Willem Bartel van der Kooi provides the first glimpse into the technical foundation of Otto de Boer. Under this guidance, the young painter begins to master the precision required for the subjects that would define his career. By 1824, the quietude of a Dutch studio gives way to the movement of a grand study tour. Alongside his companion Gosling Posthumus, de Boer moves through Germa…