What are some of the techniques?

[carcrave]

I did see something online and am curious on how it was done.  It looks like it was airbrushed but not really sure.  It also looks like opaque powder colors were used for the stencils.  I use 90 Bullseye only. I would like to know if you were to use a stencil if it would have to be adhered to the glass so you would get a clean edge of your design. So any ideas or products out there?