Largely self taught, his lack of formal training does not interfere with the artist's adept treatment of light and balance of color when depicting South African landscapes. The closest "ism" to this individual's technique is Post Impressionism.  Roon combines many colors using thick paint (impasto) to depict scenery, wild life, villages and hills or coastal scenes. 

One of the founding members of the Artists Market, Gerritt has participated in teaching and promoting the talent of new and young South African artists.