Jigsaw Puzzle?

http://www.puzzlewarehouse.com/How-To-Gl…
discusses various glues and methods.
Me, I think it’s an awful thing to do to a puzzle. I can see sandwiching it between mat board and Plexiglas and adding a frame, preserving the potential for original use.

Use Thompson water sealer or similar. That way it will “glue” the pieces together on the picture side w/o ruining the Pic

i just use common elmers glue and it works fine i have 7 glued puzzles on the walls of my living room