Sealing ink onto glass drinkware
I have begun hand-painting glass drinkware with Ranger alcohol inks. I tried many things as varnish/sealant, all of which damaged the surface in some way. (I tried several Krylon sprays, a Mod Podge spray, Golden GAC 700, Golden Matte Varnish, and Ranger's own brush-on varnish.) I read an article about baking them for half an hour at 400, so I did that.
Now I have some that I would like to put up in my Etsy shop. However, I'm nervous that the designs won't last, especially if buyers treat them harshly. I can put up a disclaimer, but I would rather know that buyers will get to enjoy them for a while.
Is there anything else I can do?