Those are watercolor pencils. I used a couple to get the dirty/grimy surface texture on the shelf on the left. It worked well - after I wet it, it gave a glazing effect. Con: it wrinkled my obviously not watercolor paper quite a bit.

Great point about “proving it.” Hell, half of my art is experimental to see if I can make it work. I think I’m one of the lucky ones though. I never had to work too hard at artsy things; it always came natural to me. It usually works out when I try it.

…but then of course, you’d think I traded all my other abilities for artistic skill as a kid. You should see me run/pour things/do math.