Nieuwenkamp didnâ€™t start painting until 1921, when he was staying in Rome. His paintings mostly depicted scenes from India and the Netherlands East Indies. He only started to embrace this art form in his later years. The fact is he believed artists should learn how to draw properly, before starting to paint: 'All the great painters that I know of have drawn first.' He experimented and also destroyed a lot, because ultimately he was not satisfied with the results. Only later did he discover that an oil painting could easily be modified, whereas a drawing or a watercolour could not.
Even as a painter, people couldnâ€™t pigeon-hole Nieuwenkamp, and actually they still can't. His use of colours and techniques for his often large sized paintings were quite unusual. However his paintings don't differ significantly from his graphic works. His style is somewhat equivocal, a combination of:
- a detailed, intellectual and objective expression of reality, and a tendency toward stylisation, shading using flat and little expressive colour;
- a rhythmical and decorative line pattern, creating a somewhat oriental impression;
- his paintings retain their drawing-like character. Ultimately, Nieuwenkamp will continue to create, using his old/ skills. His oil paintings follow naturally from his drawings.