cereal boxes contain lots of rubbish in the inks! – dont use em
old birthday cards and the like are the best
or get a bong 
I slept with faith and found a corpse in my arms on awakening; I drank and danced all night with doubt and found her a virgin in the morning.
Aleister Crowley (1875 – 1947)
Blackboard paint – Covers a multitude of sins!