Situation:
- Built a lot of gridless TLX tiles.
- Don't know for sure if players will like the movement-by-ruler/tape measure (as of now, we only played grid-based board games like Descent etc.)
Question: Is there any kind of transparent, sticky-but-not-gluey plastic sheet that I can print a 6x6 1 inch grid on so I can just stick those onto my gridless tiles and have instant grid-based movement without having to build all new tiles? Maybe something that works with static electricity? The main idea, of course, is that I can remove the grid equally as easy as putting it on.

Seems like you are going to have to fit them underneath the anchor tabs on the tiles anyway...so could you just cut the transparency so that the tabs hold it in place ?

Spray a varnish on on the tile itself, then put a drop of water on it with the transparency?