2x2 Holders....how Long Are They Good For?

Another thanks for the replies!

I have a couple dozen that date back to the late 60's (yes, I am that old) the staple is a little rusty and the white cardboard is now light yellow, but the mylar is still is good condition. I truly think that mylar used back then was a little thicker. I see no change damage done to the coin, other than some faint toning on some. I have a couple of UNC Roosevelts that still have GOOD Luster. I see no problem at all with long term storage.

2X2 from the very early 1960's. You be the judge.

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The best 2x2s are probably Eagle mounts. They are expensive compared to cardboard and thicker so may not fit into regular albums although you can get albums that fit them.

To answer in a reverse post method: Learjet has sort of hit the nail on the head. In reality, over the years there have been many varieties of 2x2's produced and the properties of them varies with the manufacturer and time frame. I've had coins in some for well over 20 years and no problems. In the past many types of plastics have been used. Some may well be PVC. Some plastics do not last long at all. If you were around with some convertible cars in the 50's and 60's, the rear plastic windows would eventually turn yellowish, dry and crack. Just that type of plastic. Mylars have life expectancy of 1700 years so if your 2x2's are Mylar, they should be safe for about that long. The cardboard also is different with different manufactureres and the time frame but since it does no contact the coins, makes little difference.
Jim1953. I presume you mean a Copper coin that is now green. Note that the term Verdigris is used by many to discribe Copper turning green when in reality, Verdigris is Copper reacting with an Acetate, not normal air/moisture. What you have seen is Copper Carbonate which is normal when Copper is exposed to CO2, H OH and O.
ElleKitty: Great suggestion. However, pliers are on the market with such flat tips and even ones that are hindged so that they close straight, not on an angle. Also, here is another tip. If you have the standard Swingline Brand Stapler. Note that most models have a removable plate where the staples hit. This is made so you can make the edges of the staples go in or out. If you know how to make a new flat plate to put in that location, the staples will be flattened by normal pressure of installation. Problem is the direction of the tips are not predictable.

NO, it was my Grandmothers, and sad to say, the missing leg had "help" leaving the coin. I always assumed it was real until I took pictures of it several week ago. The close ups clearly show the tool marks. that is why I left it in the old holder. it is more of a keepsake than a collectors coin.
I posted the closeup pictures on the error forum (topic: is this a 3 leg?)

Ive had some problems in the past with the cardboard "dust" causing spotting. But I found if I use a soft cloth to wipe them down before mounting the coin I haven't had a problem since
Jeff