The following year he went to the German town of Cleves, where Barend Cornelis Koekkoek had founded a drawing academy.
In 1858, Gabriël introduced Anton Mauve to the area, who would return there ten years in a row and would become good friends with Gerard Bilders, the son of Johannes Warnardus.
Helped by Roelofs' suggestions, he developed into a good landscape painter, with a clear palette.
Gabriël's paintings stand out from the 'grey tones' for which the Hague School was famous because of his clear use of color.
From 1862 onwards, Gabriel regularly embarked on study trips to the Netherlands: first to Arnhem and Oosterbeek, in 1866 to Veenendaal, in the seventies to Abcoude and Vreeland, and from 1875 to the lakes around Nieuwkoop near Noorden.
In 1886, he stayed with the Mesdags at their home in Vries in Drente, where he made studies of the fields, barns and farms.