By: Skip Marshall
Member American Numismatic Association
American Numismatic Society
Georgia Numismatic Association
Now that you have spent a lot of time and energy cleaning/restoring your ancient coin treasures, you will probably want to store them in an organized way. If you are new to coin collecting, the options can be intimidating as well as confusing. Each option has advantages and disadvantages and some can be downright dangerous to the surface of your coins. Here is a list of some common storage and display products.
Cardboard 2×2 holders
Chances are, if you have done any kind of coin collecting, you are familiar with this product. These cardboard holders have a round window covered with a Mylar film. You place the coin over the film in the window, fold, and staple together. Some types even are self adhesive.
Advantages
- Inexpensive.
- Easy to view coins.
- Ability to write information directly on holder
Disadvantages
- Cannot remove and replace coin without ruining the holder.
- Care is needed when removing coins so as not to scratch the coin with an exposed staple
2×2 Soft Plastic Flip
Many coins that you purchase will be housed in a soft clear plastic 2×2 flips. They are made from PVC which is short for Polyvinyl Chloride. These are great from a dealers perspective because they allow the coins to be easily inserted and removed. There is also a space to insert a label.
Advantages
- Inexpensive.
- Easy to view coins.
- Easy to insert and remove coins.
- Space to add an insert label with room to record a lot of information.
Disadvantages
- PVC
THE FOLLOWING IS IMPORTANT! PVC can damage your coins! Plastic flips that use PVC are NOT suitable for long term storage. The plasticizer used to make the plastic can leach out over time and react with the coin. Notice that the last letter “C” stands for Chloride. These Chlorine atoms can react with Hydrogen to form Hydrochloric Acid, and acid and coins don’t mix very well (at least for the collector). A tell tale sign of PVC damage is a green film forming on the coin, commonly called “Green Slime”. Once it forms, it must be removed or damage will continue even if the coin is moved to an inert holder.
The good news is that this won’t happen right away. It depends on a number of factors, including sunlight, heat and humidity. In general, as these increase, the likelihood of degradation also increases. This could be months or years depending on the environment in which your coins are stored.
NON-PVC 2×2 Flips
These are made from Mylar and are more rigid than PVC flips. Be careful when purchasing them as some types advertised as being safe just have a reduced amount of plasticizer.
Advantages
- Safe for coins
Disadvantages
- More expensive than soft 2×2’s
- May crack and break with repeated use.
This is the way to go for most collectors
2×2 Paper Envelopes
Advantages
- Easy to use
- Large area to write information
Disadvantages
- Can’t see coins
- May cause toning if made from paper containing sulfur.
An old standby used for many years. If you like to look at your coins you are at risk of dropping them every time you remove one. Overall though, an OK choice.
Hard Plastic Holders
Advantages
- Good protection
Disadvantages
- Take up storage space
- Difficult to remove and replace
- May not be sized for ancients
These holders are usually in the form of a snap together set. The can look nice and offer good protection, but odd sized coins may rattle inside causing damage. Also, they are not necessarily air tight.
A Few Other tips
- Always handle your coins over a soft surface. Dropping a coin on the floor or other hard surface can cause damage to the rims. In some cases, where the ground conditions have caused the metal in the ancient coin to “granularize”, the coin may even break.
- Avoid touch the surfaces of the coin. Hold a coin by the edges whenever possible.
- Try not to cough or sneeze on a coin. Moisture droplets can cause unsightly permanent spotting over time.
- Check your stored coins once or twice a year. Look for signs of environmental damage.
- If possible, try to keep your coins in an atmosphere controlled environment. A dry closet would be preferable to damp basement or hot attic.
- Keep an open container of silica gel to control the moisture of the storage area and change it regularly. This is especially true for safety deposit boxes which may be subject to humidity fluctuations.
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