I am planning on getting some plastic 2x2 flips, and I see both of these kinds on eBay. Which kind is better for long-term durability and protection of coins? I will be using these for patinated ancient Chinese coins, so coin safety is not as much of a concern.
I use plastic for any coins or currency that I am going to move around, such as taking to shows or passing around at coin club. Under most conditions, these will release PVC softener over a long period of time. The non-PCV "safety" plastic is so hard it can damage the coin and the plastic eventually becomes so scratched up and "cloudy" as to be unappealing.
OH, one more thing. The non-PVC holders crack very easy and one can loose the coin , drop it and possible damage it.
I guess it depends on how you envision the use case for your "storage." The only possible rationalization for PVC-based flips is temporary storage for use in conjunction with shows and sales-based environments - Mylar is admittedly capable of scratching nice coins if you insert and remove them often enough, and will eventually crack with repeated handling. A few days in a (new) holder of the PVC type won't hurt anything. But you're not "storing" it if you handle it that often.... Me, I image my stuff in sufficient detail to forestall the need to ever "handle" it again - the images are all the "handling" I need once they exist - so Mylar flips are a strict rule in my collection. PVC plasticizer degrades into hydrochloric acid (among other things), and patina won't stop that. I'm just_not taking the chance.
Yes, soft plastic flips are certainly not a safe way to store one's coins. I handle and move my coins quite often and am in a different scenario than most collectors.
That's what I am currently using. I like being able to see the actual coin without having to take it out.
That takes the fun out of holding the coin! Wondering if taking the coin in and out of an envelope wears the coin more than a flip.
My only worry about paper is the chance of eventually toning the coin. The old days of high-acid paper are over, but all the same they all still outgas something eventually over time. It's pretty much the only way to create the paper. Maybe I'm too hardcore about it, but my first thought when the desire to fondle my coins appears is my commitment to the next owner's enjoyment, and those after them. Coins aren't supposed to be frangible.
Collectors of moderns face different realities than ancients and everything @SuperDave said is reasonable and should be considered. I've considered going to envelopes because I do like to handle and inspect my coins frequently. I'm using Saflips right now and they're great for my tokens but with my ancients they may not be the best.
