Wet paper isn’t, but if you dribble some grease from your McWhatever on some paper, it can become nigh transparent.
They used buttered paper for windows back in the frontier days when it was impractical to obtain panes of glass. Very clever! Even waterproof, to some degree. Though you do have to worry about your windows going rancid.
Why do does it work?
Oh, for the love of Mike. I can’t believe this. I did a search, found nothing (should have tried “oil” in addition to “greas”), then posted a question that I’ve been mulling over for weeks, then, right after starting a new thread, I found exactly the same question, right down to the early American windows, in the Wet Tshirts thread.
Mods, feel free to lock this thread.