Kointains were developed and introduced in the 1940s by E&T Kointainer, and have been a popular solution for protecting and storing coin collections since their development. Each Kointain is made from a thin, pliable Mylar that is virtually invisible when placed on coins. Kointains unique convex design means only the edge of the holder is in contact with the coin, while still maintaining a virtually air tight seal. Kointains are also unique in that they allow all of the coin to be seen, including the edge. Kointains are a very flexible holder (for those collectors looking for a more rigid holder, we suggest Air-Tite coin holders).
Kointains are not just a great value that has been proven safe for long term storage, they are also used to store some of the most extensive coin collections around the world. Kointains are used by the National Numismatic Collection at the Smithsonian Institution, if they trust Kointains you can too.