1. Purchase a jar of liquid puzzle glue. If you are lucky, your puzzle has the glue included. If not, you can order liquid puzzle glue from an online puzzle store. You might also locate puzzle glue at a craft store or specialty shop.

  2. 2
    Place the puzzle picture side up on a flat surface.

  3. 3
    Protect the surface your puzzle is lying on by placing a piece of thin plastic or parchment paper underneath the puzzle. If you know before you begin piecing the puzzle together that you want to keep it by gluing, it would be a good idea to piece your puzzle on the plastic or parchment paper. Otherwise, you will need to carefully transfer it over. This will keep the puzzle from sticking to the table when you apply the glue.

  4. 4
    Coat the surface of the puzzle with a thin coat of liquid puzzle glue. Apply the glue to every piece. Check to see that the glue is getting between the pieces.

  5. 5
    Give the glue around 2 hours to dry. Check the label on the glue to be sure this is the amount of time it takes for your particular type of glue to dry.

  6. 6
    Repeat with several thin layers of glue, allowing the glue time to dry between each coat.

  7. 7
    Check to see that the puzzle is similar to a piece of cardboard when you are finished with the gluing and drying process.