Although the name is "Brussels witloof", where "wit"stands for "white", the subject tends to be yellowish greeny white. It's my third attempt to draw a white subject on a white background. And yet again the whiteness is suggested by using colour. Interesting how your mind translates the information seen through your eyes. Pen and ink and watercolor.
Another attempt to draw white subjects against a white background: mushrooms. Luckily these weren't as big as the ones we once grew by ourselves. That was a fun thing to do, growing our own mushrooms. Very easy with a 1-2-3 starterskit, but it became such a success that we couldn't see mushrooms for a while! Pen and watercolor.
As an ongoing practice I sometimes put a test on myself. For instance drawing white objects against a white background. I thought some pieces of garlic would be a nice challenge. It turned out to be less difficult then I was afraid of. When I looked close at the garlic, I saw all kinds of colours hidden in what I thought was a white surface. All I had to do was to exaggerate those colours to give depth and 'life' to the drawing. Pen and watercolor.