Renaissance Wax is by far, hands down, the best polish you can use to protect your collection. Developed in the British Museum Research Laboratory by Dr. A E A Werner in the late 1950s, it is a microcrystalline wax polish used in antique restoration and museum conservation around the world. Suitable for use with wood and metal, the wax creates a protective layer that will protect and rejuvenate.
To use, simply rub a bit of wax on the pieces with a clean cloth. A little bit goes a long way; you'll be amazed how long this jar will last.
Renaissance Wax is made in the UK. Product safety data is available here.
Gives a subtle bump in beauty to your puzzles while providing a sheath of protection. It was a surprisingly pleasant experience using this product. It gave me an opportunity to admire my puzzles.