Not being a huge fan (yet) of PEI print surfaces, I grabbed a Prusa Borosilicate bed that I had lying around collecting dust. Checked the size and it fits rather well over the current PEI surface and is heating up nicely. I will need to check the temps, but by hand it feels the same as the surface below it. Here are a few pictures of my awesome mod for now... Tape! The bed was not perfectly clean, I was mainly just wanting to see what the auto-leveling would do with it. After this print I will properly clean, go through all the wizards again and print something else correctly. NOTE: My print quality is suffering from bent rods, so my pictures do not represent what the R2 print quality is fully capable of. You will see vertical ringing and shifting layers in my machine due to the UPS soccer match on my box... My reason for testing this was how thin and scratchy the stock Robo R2 print surface is, plus the maintenance nightmare of trying to replace it. I fully think it will be possible to print PETG glass holders that stay out of the way of the extruder and other internal objects. I plan to fully explore this option and design something to share with everyone. The bed I am using is 3mm thick. Any questions please let me know.