Newspaper. Lots of it
Cardboard gift wrap rolls. Lots of them
Bags of rice
Bags of unpopped popcorn or beans
Paper Maiche power glue
White latex house paint (for priming papers and canvas)
Extra craft or art supplies people might have handing around
Some plywood sheets and 2x4s (Husky platform)
Heavy Duty Locking wheels (Husky Platform)
Paint brushes ( all kinds)
canvas or plastic drop cloths.
Books about drawing anime figures, superheroes, animals, etc.
Shelf stable snacks. (Its a long time since lunch!)