"ROK" 

Rok™ chalk combines the impermanence of traditional chalk with
the versatility of spray paint.  With Rok™ chalk you can mix colors 
and consistencies to get the perfect spray.  The Rock™ chalk spray 
can also allows you to customize the amount of pressure in the can,
making sure you have full control of the paint.  Rok chalk is also
 easily washable and fades with time.  With Rok™ chalk you canpaint anything. 

(This was a group project with a fellow designer Alexander Calachan  http://www.coroflot.com/eightysea)