After receiving training as a draughtsman, Heyboer made works consisting of landscape drawings and cartoon illustrations, later creating etching plates that he then sold on to printers. Some of these are directly related to the work of other popular artists, as he created them on commission. In the early war years, he made some illustrations for the Joh. Enschedé company, one of the few Haarlem businesses that was still able to support young artists. From 1950 he was in the SBBK and for his “Contraprestatie”, he submitted works regularly. This was a support scheme whereby Anton was dependent on the judgement of the artist-commissioners in the judgement committee, and during the years he was in the program these were Levinus Tollenaar and Mari Andriessen.