If it is real glass, then Armour Glass Etching Cream would frost the glass to make it translucent.
Ok, I was just curious because I know with glass there are ways to chemically etch which is much simpler and cheaper than sand blasting. This is the stuff I have used: http://www.amazon.com/Armour-3-Ounce-Glass-Etching-Carded/dp/B003W0MUVW/ref=sr_1_1?ie=UTF8&qid=1462888691&sr=8-1&keywords=glass+etching
I would suggest trying it out if you do glass, it works great and you can use paper or masking tape to stencil.
None the less, these look amazing! Great Job!
How about etching creme?
https://www.amazon.ca/dp/B003W0MUVW/ref=cm_sw_r_cp_apa_fabc_mdB.FbA473PG6
You could buy this stuff and make it permanent.
I'm guessing he/she made a stencil and used some glass etching cream. I kinda wanna make one of these now...