Not your boss's bland cork board

The cork I’ve used, at least (there may be different corks?) takes very little encouragement to turn from cork to soot. I think you could wave a flashlight in its general direction and it turns black. Which means you get great contrast, but there’s not much opportunity for grayscale. Probably better to use dithering than vary power, and tweak any photos to be on the light side.

There’s a coaster I made at the end of Vary power glitch (+ workaround) that came out pretty decent. I’d still lighten it up even more if I did it over.