

Graphite and wood dust.
Basically pencils work by rubbing graphite onto paper. With normal gravity that dust falls to the ground, but in space it can float around and cause problems. Same issue with sharpening pencils and all the wood dust.
https://www.sciencealert.com/why-wouldnt-nasa-want-to-use-pencils-in-space-heres-the-true-story








It’s a California Roll, so I guess that makes sense.