Just as a follow up to my comment about the sugar-water. I’ve got even better results with much less sugar. 50/50 made the plastic stick to the sugar itself but not so much to the actual bed. Last experiment was a bit unscientific so I don’t have the exact numbers but I would say I am at around 20% sugar.
I pay €44 EUR for 2.3kg. It is very difficult plastic to work with but at least it is cheap. It doesn’t stick to glass or kapton. but with pva (woodglue) on glass it stays on just fine. Mine is from Plastic2print.nl