I do not use 2x2 holders because of the staples. You tend to get what you pay for. Fortunately the proof coin can be re-slabbed for a price, an expensive lesson learned.
Here’s a case of do as I say, not as I do . . . Bring some oversized 2 1/2 x 2 1/2 flips to the show with you. When you buy coins in stapled holders, slide those holders into the oversized flips, and carry those in your pocket. The only reason I haven’t done that is I almost always have boxes with me at shows, and don’t need to do that.
I posted this thread to give folks an idea of the danger of staples. Seems like a lot of images of 2X2s get posted that need to have the staples smashed down. I have found that staples can also put tiny holes in the mylar of a different holder that creates a nasty toned spot on the coin where the hole is. You will also see where the staples can create black spots around the rim of the coin even if you smash the staples down.
does anyone have experience with the self adhesive 2x2 holders, such as from Lighthouse? I guess my concern would be whether there is off gassing from the adhesive.
Not sure about the gassing, but I was looking through some that a dealer had. They were hard for me to hold and flip, kept slipping from my fingers.
Yes, I use these for RB and Red copper and proof silver coins. The manufacturer says they are safe and I see no reason to doubt that. The adhesive should do a good job of sealing the coin from the atmosphere and its moisture, which is the major contributor to copper changing color while in the possession of a collector. The only thing I think you have to be careful about is the cardboard of these adhesive 2x2's is thinner than that of the standard, staple-closed type. As a result of being thinner the surfaces of the coin stand more proud of the carboard surface and are thus more susceptible to damage from stacking, sliding, and jostling even if the clear enclosure is not breached. There are multiple ways to prevent or mitigate the exposure that are too numerous to state here simply because how you deal with it is the result of how you are storing your coins.
This $14 tool can help make all staples flat. I prefer it to pliers. https://www.homedepot.com/p/Crescen...MIq7rbwPW17QIVtsmUCR1pqQUkEAQYHSABEgKshfD_BwE
I decided to switch mine to coin capsules. Then I got small ziploc bags to put the capsule in. I write my notes, info on the ziploc. The capsules and ziploc are cheap compared to the cost of one damaged coin.
Many times over the years I have suggested squeezing the staples with pliers when I see the problem in posts. A few times I got a mind your business response. I just use flips that are PVC free. They do get brittle after a while so I just replace them. Constant battle.