Most of your Arkham Horror LCG collection sleeves just like Magic or Pokemon cards, but a specific subset - certain investigator cards and some accessory cards - uses a noticeably smaller format that trips up a lot of new players. Standard sleeves simply don't fit these mini cards, and buying the wrong size wastes money on sleeves that won't do their job.
These smaller cards measure roughly 1.625 inches by 2.4 inches (41mm by 63mm), a meaningfully different footprint from the standard 2.5-by-3.5-inch cards that make up most of the game. Side by side, the size difference is obvious, but it's easy to miss if you're sleeving a mixed stack quickly without checking each card first. Fantasy Flight Games uses this smaller format sparingly, so most players only encounter it once they start collecting investigator-specific accessories rather than during their very first game.
Because these mini cards tend to be investigator-specific or accessory cards you'll reference constantly throughout a campaign, they actually see a lot of handling despite being a smaller portion of your overall collection. That makes proper sleeving arguably more important for these cards, not less.
This guide focuses specifically on identifying which cards need the smaller sleeve size, what sleeve options actually fit, and how to avoid the most common mistakes when sleeving a mixed-size collection.
Before sleeving anything, sort your investigator cards and accessory cards separately from the rest of your collection and check their dimensions against a ruler if you're unsure. Mini cards are noticeably smaller in both height and width compared to standard cards.
Doing this sorting pass once, early on, saves you from discovering a sizing mismatch halfway through sleeving an entire box of cards.
A standard sleeve sized for 2.5-by-3.5-inch cards leaves a mini card loose inside, shifting around and offering essentially no real protection against bending or edge wear. The excess space inside the sleeve also makes shuffling awkward and increases the odds of a card slipping out entirely.
This isn't a close call - the size difference between standard and mini formats is large enough that there's no reasonable workaround using standard-size sleeves alone. Trying to make do with the wrong size usually ends up causing more handling damage than sleeving the card at all.
A snug-fitting mini card holder, sized specifically for the smaller 41mm by 63mm dimensions, protects these cards the way a standard sleeve protects your larger cards. Snap-style holders in particular give a secure fit that keeps the card from sliding around during handling.
If you can't find a dedicated mini-card sleeve locally, double-check the exact millimeter dimensions on any product you're considering rather than assuming small-sounding sleeves are all interchangeable - mini card formats vary more than people expect across different games. Mini tarot card sleeves and small playing card sleeves from other hobbies sometimes fit, but always confirm the measurements before buying a batch.
Investigator cards in particular get referenced throughout an entire campaign, meaning they're handled far more than a typical encounter card that only comes into play for one scenario. That repeated handling makes proper mini-card sleeving a genuine priority, not an afterthought.
Consider keeping your sleeved investigator card somewhere easily accessible during play rather than buried in a deck box, since you'll likely be checking it throughout each session. A dedicated playmat slot or small stand near your play area keeps it visible without adding wear from constant handling.
When sleeving a large batch of cards from a new expansion, separate mini and standard cards into two piles before you start, rather than sleeving as you go through the box in whatever order the cards come out. This simple habit prevents the most common mistake in this whole process.
Labeling your sleeve supply boxes by size also helps if you're sleeving across multiple sessions, so you're never guessing which stack of sleeves fits which pile of cards. A few minutes of upfront sorting saves a lot of frustration once you're a few expansions deep and juggling multiple sleeve sizes at once.
Roughly 1.625 inches by 2.4 inches (41mm by 63mm).
No, standard sleeves are too large and leave the card loose and unprotected.
Certain investigator cards and some accessory cards.
Investigator cards in particular get referenced constantly throughout a campaign, so they see heavy handling.
Get the right-sized protection for your smaller Arkham Horror cards from EVORETRO's Card Protectors Collection.
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