I had a NJ Transit commission that involved etching images onto glass
blocks. I contracted out the etching but the fellow who did it had a
little glass enclosed box that he put the glass block in and then slid
his hands into the gloves that were part of the box and sandblasted it.
It went very quickly.
I edited the drawings in Photoshop and gave him computer files on a
disk which he used to create masks for the etching. You can see the
project at: