I use the double-stick tape that comes with window film kits since there is plenty left over but you can use any kind of double-stick tape to hold the grid in place.
I have been using so-called “transfer tape” (3M is a common brand but there are others) that in essence can make anything into peel and stick. It is very thin, transparent, and I have it in 1" and 3/4" widths. I do not see it at office supply stores but rather at craft/art supply stores. It isn’t cheap but it is so thin that a roll goes a long way - my two rolls will likely out live me! [xx(]
I think you can get the clear peel and stick and run it through your printer to apply the grid. If you cut it to pieces just print off another one. As well you could print off different size squares as required.