I have been printing with PETG on glass for a little while now, and have gone through almost an entire roll. Yesterday I had my first print stick so hard that it delaminated the glass :(. I stopped using hairspray as it made the prints not stick at all, and printing bare glass was just fine. But something about yesterdays print made the glass give up. Is this how PETG + Glass normally fails? Works perfectly for years, and then suddenly fails?
Yup, in hindsight that seems obvious. But i never had super strong adhesion to begin with, so I assumed it was fine. And my impression was that petg glass failures were something that happened instantly, rather than a gradual thing.