Bram Bogart ranks amongst the principal artists of the 'Informel', the large post-war movement, which abandoned geometric abstraction in favour of a more intuitive form of expression, similar to action painting, but often a lot more gestural and textural. Bram Bogart worked at the heart of the movement, which included Alberto Burri in Italy, and Antonio Tàpies in Spain. In 1946 Bogart settled in Paris for a decade, where he developed his signature technique of brushing, dripping and pouring layers of matter onto the canvas. His Parisian paintings are monochrome in palette and almost romantic in their expression. His move to Belgium in 1959, coincided with a change in style: painted in wide confident strokes, often using strong colour, the 1960s paintings frequently reflect Bogart's deep connection to Nature. Although Bogart has used the same technique since the early 1950s, he has always been able to renew his painting and is considered a pioneer of post-war 'matter' painting.

Witzwartzavel is typical of the early 1960s work, being direct, masculine and physical in its execution, yet composed, romantic and subtle in its appearance.

The work of Bram Bogart is present in the following museum collections: Museum Boijmans Van Beuningen, Rotterdam; Guggenheim, New York; Musée du Louvre, Paris; Centre Pompidou, Paris. In 2014 Tate Modern acquired four works by the artist.