How did he do this?!

[readyjimm]

im curious how this man did this, and if someone has a old sail they would send to me (ill pay the shipping) i really want to try this!

 

[Rob B]

I'd say black majic marker and an overhead projector to get the image on the sail for tracing.

 

[jonk]

im curious how this man did this, and if someone has a old sail they would send to me (ill pay the shipping) i really want to try this!

If you want to get detailed you may consider using a stencil
http://www.instructables.com/id/Large-Stencils-via-Projector/

What kind of paint would be ok on a sail? Spray paint?