New York, NY
According to the opinion that glass is not bole’a, does that change if the glass is painted?
Interesting question. Even if the paint is bole’a, you should be able to do hagalah, no reason to think it is like cheres. Also, it is extremely thin, so the amount that it could be bole’a is miniscule. The Taz says that Chazal never forbade use of something lekhatchilah if it would be mutar bedieved, meaning if even when you used it ben yomo it would be bateil because it is so minuscule, it wouldn’t be assur as an eino ben yomo. In short, I would definitely assume it is fine if you kasher it (and possibly even if you don’t, if you assume that glass isn’t bole’a).