All modern coin sets and coins should be bought and sold in original cases and capsules. The Mint sells coin sets in protective plastic cases called lenses or in folders. Individual coins are packaged in capsules fitted into folders or boxes.

In addition to original holders, other storage options include 2" x 2" cardboard or plastic holders, plastic tubes or capsules, sleeves or envelopes, and albums.

For high-value coins, use hard plastic holders. Professional coin grading services use sealed holders called slabs to protect authenticated and graded coins.

Use acid-free cardboard and plastic holders free from polyvinyl chloride (PVC). Acid and PVC can ruin a coin’s surface. PVC eventually coats a coin with sticky green slime.