In 1983 Gertjan started modeling after he walked a fashion show at Willem de Kooning Art Academy of a colleague student. His school teacher sent him to a model agency and so his career started. For seven years he worked fulltime as a model and then abruptly stopped when he started his own agency MAX Models Rotterdam (1990).

During his early modeling career, Gertjan worked worldwide, mainly for catalogs department stores, and many fashion brands. Every season he tried the Milan fashion week and he walked the catwalks for Valentino, Byblos, Cavalli and many more, followed by editorials for LEI, VOGUE, L´Homme and the worldwide campaign of designer Fujiwara. 

After he sold his model agency in 2014 he moved to the island Ibiza and started working as blogger/photographer for a house rental company. Since 2018 he re-started his career as a model at the age of 54. Since 5 years Gertjan lives in Spain. When not working as a model he makes art (paintings, illustrations) and designs cushions under the name GERT DESIGN which he sells on the Las Dalias Hippy Market. He loves to write, make photos, film and edit and make music on Ableton.