Maybe it started with a coin your grandfather gave you, a shiny gold disc you knew was worth a little something. Then it grew into more shiny coins, each with a history, sentimental value and potentially, real investment value. You realize it’s time to learn more about coin collection storage to preserve what you’ve got.
After all, it’s important to properly store your coins to keep the metal from deteriorating, thus losing value, explains Shaun DuBois, numismatic (or “coins”) director at Pacific Coast Coin and Collateral. He shared his tips for keeping coins safe and organized.
“Most coins are valued according to their condition or state of preservation. Proper storage helps keep coins from degrading or picking up marks.”
In other words, you don’t just want to keep your coins loose in a sack, which can cause them to rub against or hit one another. This is especially true with “uncirculated” coins, meaning those that did not go out in the market to be handled or spent, thus they are free of any wear or damage.
He also suggests using cotton archival-style gloves when handling coins of value such as “proof coins” (special early samples of a coin issue popular with collectors). “Acid and oils from your fingers, if heavily impressed into a coin can cause permanent finger prints etched into the coin. It is very unsightly and therefore a negative to value,” said Shaun. “Also, you should always handle a coin by its edges and never grip or squeeze a coin.”
For coin storage, Shaun has a few suggestions for optimal protection.
There are plastic sleeves often called "coin flips" (see photo, right) made from plastic, vinyl or mylar. You can also opt for plastic 2x2 cases (see photo, left), round acrylic "air tites,” or “coin sleeves,” which are two pieces of cardboard with a mylar window to see the coin. All of these will hold the coin safely in place and protect it.
Coins placed in these types of sleeves can then be stored in archival-quality storage boxes.
More valuable coins can be placed in a "slab," a thick, snap-close, acrylic case that provides the most protection. If you have a number of loose coins you’re keeping for investment, rather than display, coin tubes are a good way to go.
Or if you prefer to keep your coins in a book style, where you can turn the pages and look at your collection, coin albums might be for you. All of these storage items can be found at most coin shops, or they can be ordered online.
When storing your coins, you want to keep them in their protective casings as much as possible, “Since most metals react with oxygen in some way, even the smallest amount of oxygen in contact with a coin will cause damage,” said Shaun.
And while it’s tempting to polish up your coins before putting them inside a nice, fresh case, Shaun also cautions against cleaning them. “You should almost never try to clean or alter your coins from how they are currently, as the value of most coins is based on their originality and numismatic integrity. If you were to alter them then you can potentially strip the coins of what most collectors prize and look for in their coins, thereby harming their value and causing them to be worth less in the marketplace.”
Lastly, after you’ve packed up your coins in a proper storage holder, find a good storage space for them. Shaun says the environmental elements of that space are important. “Having them in in a space subject to low temperatures could cause moisture to develop and spot your coins. Humidity can cause coins to corrode or spot, as the water reacts with the metal. Also, if the temperature goes too high, it could accelerate tarnishing that is potentially unsightly.”
Anywhere that is comfortable for humans is probably good for your coin collection too. With some care and proper protection, coin collecting will offer you a hobby than can be both fun and offer the maximum return on your bright and shiny investment!