Do you mean the skill which allows you to write on the ground or the one to draw your guild emblem on things?
The one where you draw the guild emblem is not implemented by gravity (bishes... it's probably the most fun skill in the game)
To get the skill to write on the floor you'll need the following skills and skill levels (IIRC)
All the pre-requisites for gangster's paradise.
Gangster's paradise
This should unlock the cleaner skill.
You need this at a certain level to get the skill
