Johan Koeleman studied at the Grafische School and the Kunstnijverheidsschool in Amsterdam. He broke off his studies in 1946 to work in an advertising firm. Koeleman continued to do advertising art until 1969. Between 1954 and 1960, he made his first and only comic series for publisher Mulder & Zn., called 'De Avonturen van Pinkie Pienter'.
Although it was a primitively drawn science-fiction comic with a lot of robots and flying saucers, it captured the heart of many young Dutchmen. The series was taken over by Lex Overeijnder, and finished by Berend Dam. The comic was also translated to French ('Martin Malin'), German ('Fritz Pfiffig') and English ('Ronny Roberts').