Balinese Christmas exhibition
After his return he worked predominantly on his books and paintings. In the winter of 1937 the Adult Education Centre in Rotterdam held a huge Balinese Christmas exhibition where the artefacts that Nieuwenkamp had purchased on Bali and a number of his lithographs and etchings were sold.
Two handwritten manuscripts, describing this journey, have survived, the last one dating from around 1945. They contain a lot of sections of text because many of the drawings had not been published before.