Look at this, it's a thing that writes stuff in water on a dry surface 

水书法器 Water Calligraphy Device - BJDW Clip from Nicholas Hanna on Vimeo.

Now if only I could hook that up to my rustler, speed up the writing process and head to the track on a day when the track hasn't been watered down ... EAT MY DUST
Source: Commuting 253