Preserving Collectibles column from the June 29, 2015, issue of Coin World:
This month I would like to discuss the care and preservation of wooden nickels. Special thanks go to the folks at the Old Time Wooden Nickel Co. who kindly answered all of my questions (www.wooden-nickel.com/). The firm has been making wooden nickels since 1948.
Wooden nickels are made from round wooden blanks that are stamped on both sides with an image or slogan.
Over the years, a myriad of inks have been used to stamp the designs. The type of ink used depends on the time a nickel was produced and the desired effect.
The wooden blank is made from a hard, durable wood, often rock maple. Rock maple (Acer saccharum) is also referred to as sugar maple or hard maple. The same wood is used to fabricate baseball bats, furniture and toys. Rock maple grows in the northeastern United States.
Once harvested, the wood is left to dry out, or season. When seasoned, it is cut into square planks that are then turned on a lathe to produce dowels. The blanks are cut from the dowels.
Once cut, they are tumbled to smooth out any rough edges and then sorted. Blanks that are too thin (wafers) or too thick (pucks) are culled, as are any with knots or a dark grain. At this point, they are ready to be turned into nickels.
Wooden nickels are pretty durable. Being wood, they will respond to changes in relative humidity (RH). Ideally, a stable environment would be best.
Given the number of inks that have been used over the years, it is hard to comment on their stability. My advice is to err on the side of caution: assume that all are light sensitive and limit light exposure.
The inks are a concern also in considering storage enclosures. Regular readers will remember that polyvinyl chloride, particularly plasticized PVC, is not recommended for storing numismatic collections. The same is true for wooden nickels. The plasticizer in PVC is a phthalate. Phthalates dissolve many inks.