The right storage depends entirely on whether you're playing with a card, displaying it, or trying to preserve its value.
Penny sleeves: the baseline
A basic penny sleeve is the minimum for any card worth keeping. It stops surface scuffing from ordinary handling and costs next to nothing per card. If you're sleeving an entire deck to play with, penny sleeves under a set of thicker card sleeves also stop the deck's outer sleeves from scratching the cards' surfaces over repeated shuffling.
Top-loaders and card savers for anything valuable
A rigid top-loader adds real structural protection — it's the difference between a card that survives a drop and one that gets bent corners. Anything you'd consider grading, or any Double Rare and above, is worth the extra couple of pence a top-loader costs.
Binders for browsing, deck boxes for playing
A binder holds cards in clear pages, one or several to a page, and is built for looking through a collection rather than playing with it. A deck box holds a full 60-card sleeved deck compactly and is built to be shuffled and carried to a game, not displayed.
What we'd actually suggest
For singles like Koraidon or Eternatus, a penny sleeve plus a top-loader is enough if you're holding onto them rather than displaying a full set — binders only really earn their keep once a collection is large enough to want browsing.
Frequently asked questions
Do all Pokémon cards need sleeves?
Any card worth keeping should be sleeved as soon as possible, including Commons.
What's the difference between a binder and a deck box?
A binder displays cards for browsing; a deck box holds a playable deck compactly.
Should valuable cards get a rigid top-loader as well as a sleeve?
Yes — it protects corners and edges, which matters far more than surface scuffing for grade and resale value.