The biggest mistake people make in the stacking community when it comes to silver or gold, (mostly silver because it tarnishes easier), is that they don't invest in capsules. They just leave it in the sleeves. Now, sleeves are a good short term way of protecting your coin, but isn't the best way.
With my experience, they tear along the crease and they are open and expose the coin to air. Investing in capsules is the best thing you can do if you want to keep your silver coins or bars (yes they have capsules for bars too...DUH.) in a capsule. It keeps it air right and prevents tarnishing. I've had coins look mint fresh for years in air tight capsules, and they look like I just ordered them.
When you don't use capsules, you expose the coin to oxygen which causes it to slowly tarnish. Now, you don't have to use capsules if you don't care about the coin, but if you do, BUY THEM FOR GODSAKES! I hear so many people complaining about why their coins tarnish so easily. Like come on! Buy a fricken capsule. They really do preserve the coins way better than a sleeve.
