Duct tape is a bad choice if one of the goals or requirements is not to leave adhesive residue. I know this from personal experience.
A very thin layer of the stuff from glue sticks is probably what I would use because if some of it remains on the windows after foil removal, it seems the easiest to scrape off the glass with a one-sided razor blade. I have never actually used glue sticks for this purpose, though.
Scotch Blue tape is usually the best choice if you want to make sure you can remove the tape and any adhesive residue even after the tape has been in use for years, but in this particular application there are two problems with Blue tape: (1) light will shine through the Blue tape and (2) direct sunlight is the one thing I have found that will over time render the blue tape hard to remove.
I have used aluminum-foil tape for this purpose and can verify that it and its residue can be easily removed from glass (but not from the metal part of the window near glass) after years of service—although you will need a razor blade. This tape usually comes in 2-inches-wide rolls for some reason and comes attached to wax paper that it has to be (carefully) separated from before you can use it.
Duct tape is a bad choice if one of the goals or requirements is not to leave adhesive residue. I know this from personal experience.
A very thin layer of the stuff from glue sticks is probably what I would use because if some of it remains on the windows after foil removal, it seems the easiest to scrape off the glass with a one-sided razor blade. I have never actually used glue sticks for this purpose, though.
Scotch Blue tape is usually the best choice if you want to make sure you can remove the tape and any adhesive residue even after the tape has been in use for years, but in this particular application there are two problems with Blue tape: (1) light will shine through the Blue tape and (2) direct sunlight is the one thing I have found that will over time render the blue tape hard to remove.
I have used aluminum-foil tape for this purpose and can verify that it and its residue can be easily removed from glass (but not from the metal part of the window near glass) after years of service—although you will need a razor blade. This tape usually comes in 2-inches-wide rolls for some reason and comes attached to wax paper that it has to be (carefully) separated from before you can use it.