Hello
I print PLA on glass. I first clean the glass with water, then I use window cleaner and finally provide a thin layer of 3D Lac. This procedure provides superb adhesion and fine surfaces, but unfortunately sometimes objects are stuck on the glass plate. An easy method to release them from the glass is using ice spray: After cooling down the object and the glass surrounding it, you will hear a crackling noise and the object almost falls off the plate.
You can then reuse the glass plate without the need to go through the cleaning procedure again.
Regards
Andreas