He is not easily satisfied
'... I often destroyed my paintings, cut them into pieces or even burned them, especially in my early years because the fact that I was not in any way satisfied with the results of all my hard work made me desperate. I just had not developed the necessary skills yet and I did not know that one has to change a painting's composition and colour, in progress, endlessly. And that so in the end the results will always be satisfactory... '.
'... In the beginning I was still far too attached to the etching technique, where each variation was extremely difficult to create, and required much effort, while in wood cuts this was often quite impossible to obtain...'
From: Paintings' catalogue, 1948 (looking back to when he first started oil painting).