Personally i think Jean Messagier was a true Avant Garde artist. He explored paths and ways of painting well before others did and researched and developed a kind of painting which was typical for his art.
An almost spontaneous movement with the brush makes paintings and watercolors that feel organic, but these works are far from spontaneous, but well thought over works of art . It is the same as with Hans Hartung. The works look existed from some movements with pencil or brush, but designs and sketches prove that the gesture is not spontane and the result not just abstract, but a very well thought over abstract composition which is enlarged for the painting.
The same with Jean Messagier works . It is not necessary to buy an expensive painting by Messagier, because the Maeght gallery made some very nice Derriere le Miroir publication with Messagier and www.ftn-books.com has one of the most sought after CARGO publications with work by Jean Messagier available at its site.