Preserving completed puzzles can help protect your hard work and allow you to display or store them for long-term enjoyment. Here are several methods for preserving completed puzzles:
Puzzle Glue: One of the most common methods for preserving puzzles is to use puzzle glue or puzzle conserver. This special adhesive is applied evenly over the surface of the completed puzzle, sealing the pieces together and creating a solid, protective la…
Source: How do I preserve completed puzzles?