Flips

Make sure that the flip is safe for storing coins and if you plan on storing for a long time don't keep it in the flip,use a 2x2 or a hard plastic holder and make sure they are "coin friendly".
John1

Snitchard, which type of holder are you talking about? In all of my years of collecting I have never heard of the cardboard 2 x 2 mylar holder referred to as a flip. A flip has always been the 2 x 2 or 1.5 x 1.5 clear plastic double pocketed holder. They will hold any size coin that fits into them. I have always heard collectors and dealers refer to the cardboard mylar staple type holders as simply 2 x 2's (they are also available as 1.5 x 1.5).

At coin shows there are basically the 1.5"x 1/5" varieties usesd by deelers for any smaller coins. The 2"x2" for most other sizes and also there is the 2.5" x 2.5" vaieties for even larger coins or tokens or madals. All are the cardboard types of flips in either the light, medium or heavy duty type of cardboard. Difficult to really tell the difference in the thickness of the cardboard though. Really noticable if you try placing the heavy duty ones in those plastic sheets that hold 20 of them. If you get those in there, really tuff to get them out. Most people don't even realize the difference until that happens. If you store 2x2's in those Red Whitman type cardboard, two row boxes you would notice looking down how some are thicker than others if you have different types.
I've seen the two sided plastic flips also in 3 sizes but nor to much lately and don't know why. At the last coin show I was at, today, a dealer that usually has almost anything you want never has those plastic foldover flips.

I use the 1.5 x 1.5 cardboard holders for everything except silver dollar sized coins. Get more into the album that way, and storage boxes are smaller in dimensions so more can fit in my banks' safe deposit boxes.

As most already know, 1.5 x 1.5 cardboard holders come in dime, cent, nickel, quarter, and half sizes.
I use 2 x 2 and 2.5 x 2.5 cardboard holders for silver dollar and larger coins.

tyretiredwave- It can be hard to determine how long to keep a coin in a holder. Often it is just a "feel" thing based upon any possibly signs of there being moisture between the coin and the holder. As for gold, you really don't have too much to worry about. Gold almost never tarnishes. That is why shipwreck gold coins still look MS when excavated.

As already said, difficult to tell. I too have had some coins in them for a long, long time. Not even sure now but I'd guess at about 20 to 40 years. I've never worried about the condition of any coins in them though. A long time ago I noticed that if you staple them closed, air can still get in. So I started to tape up the edges instead with clear plastic typd tapes and so far, no problems. Also, much easier to open with a slit of a knife and poof, open. Also, cheaper that staples and no staple gun required.

Not really required, just send money.