Since I posted, I have tested PET bootle plastic and it will curl up at 120C. The search continues though, there maybe something out there that can be used as seamless belt! I have issues with the belts in my Automatic Build Platform. They start nicely but very soon they start bulging up at the seams and affect the shapes of the bottom on prints. In most cases is not that important but sometimes it really screws things up.The belt is made from PET and so are most beverage bottles today. I thought one could find a bottle that has a clean cylindrical middle section (no grooves or reliefs) that was around 90 mm in diameter and make a seamless belt of the section.So in order to start the quest for the perfect bootle (hopefully cheap) and not to be in a supermarket with a caliper (potentially puncturing bottles filled with liquids under pressure) I printed a gauge of sorts in my TOM.Updated the STL file - the original had some 3d text that did not print well.The bottle should have a clean cylindrical section taller than 100mm and fit snugly in the gauge. I have not found a bottle yet (just tried yesterday at a convenience store near my home) but I found something just under it ( Duane Reed seltzer). I also bought a larger Pepsi bottle to check the belt cutting process.While the bottle is still full mark the lines at the appropriate places using a permanent pen (I took the liquid out for the picture so the lines are visible). The bottle can be cut with scissors (safer). The belt is thicker than the normal ABP belt so the bottle should have thinner walls. Given that most bottles are made from the same basic starting point (the top part comes finished but the bottom part looks like a thick test tube - in the bottling plant a machine heats the piece and expands it to the customers bottle shape) one should look for tall bottles (less material for the wall thus thinner). Cover the belt in Kapton tape for better adhesion.The wider bottles produce belts that would need an extra roller (or 2) in the ABP to tension it. There is space on the back of it. That is another project in itself.I will keep my gauge in the car and take it with me when grocery shopping in the QUEST FOR THE PERFECT BOTTLE :)