Which will provide more long term environmental protection, a coin in a stapled, cardboard/mylar 2x2, or a coin in a Whitman hard plastic 2x2?
2x2's serve a nice purpose, but long term storage is not one of them. I prefer Airtites or Kontains myself.
Intercept Shields in their plastic 2x2's are my choice for the good stuff. ...Then come plastic 2x2's like Snap Tites ...Then come the cardboard 2x2's with mylar windows
Don’t the hard plastic 2x2s have holes in the corners where air can get in? This is why I prefer the old cardboard 2x2s. More fragile from head-on damage, but airtight if you staple them on all four sides. Remember, it is Mylar that is sandwiching your coin. As long as you did not leave any cardboard dust on the inside when you folded it over, that is as good as it gets as far as passive protection is concerned (not counting the Intercept shield thingies).
From the Snap Tite box (similar to Whitman's 2x2's): "Holders are made of inert polystyrene that will not harm your coins. Two halves simply snap together virtually airtight. Holders have a frosted background and a clear window. Can be used for U.S. coins or World coins by matching the size of the holder to your specific coin." As for standard 2x2's with a mylar window. Air can get into these as well. 3 or 4 staples will hold it together, but it isn't air tight. Now, the Air-Tight products are just that. However, you better make sure that coin is perfectly dry (don't even breathe...vapor droplets) otherwise you will look at the coin later and say to yourself, "What the?". That is why I like the Intercept Shields. Something needs to absorb "all of the bad stuff" that can hurt our coins. That is what I use for my good stuff. At least I sleep better with this stuff.
I guess I would agree with most of this. Although, some of my old (30 year old) snap cases definitley have a HUGE hole at each corner. I used to tape them up with Scotch tape, but who knows what fumes were seeping in from the adhesive. Fir the cardboard 2x2s, I use a size holder and staple palcement that makes it as tight as I need it to be. I really think most of them are about as airtite as I need them. Maybe I will experiment sometime by putting a small animal (a VERY small one) in a cardboard 2x2 and seeing if he survives.
Ed Zak makes a great point. Intercept has improved the technology of coin holders and set the bar pretty high. The original question was for long term storage. 2x2's certainly serve a valuable purpose, but not long term. No matter what option you decide upon, a good back up system is needed. Silica gel is a wonderful and cheap tool to use. It isn't what we see that hurts our coins, it is the things we don't see. For those using 2x2's, watch those staples
