So, a few years back, lots of suppliers had what were called sublimation whisky glasses - a frosted glass tumbler, which was the right size for standard mug presses. Unfortunately I never heard of anyone being successful enough at printing these properly without them cracking, which led suppliers to stop stocking them too.
We've had a box of them in the warehouse since, and every so often, I go back to them, determined that I'll get them to work.
Well, yesterday, I decided I'd give it another go, and try and do some personalised glasses for the family for Christmas. I actually used the pneumatic mug press thing which I'd had an equal lack of success at using to print our mugs, wound it down to its slackest pressure, and after preheating the glasses on our electric hot plate, put them in, and each one came out perfect, no cracking and all printed really well.
Things to note, are this design was not full wrap or edge to edge, one 5x5cm large stylised letter, and black script font slogan. Will have a play when back in next week to see how far they can be pushed in terms of size of print.
Only problem I have now, is actually finding a supplier who still has any left, or can start getting them back in.