The verdict

A compact deck case whose 100-card rating has a sleeve condition

I would choose Boulder 100+ when keeping a single deck compact is more important than built-in accessory storage. The maker’s explicit Ultimate Guard sleeve condition should remain visible whenever this box is recommended for a double-sleeved deck.

Choose it if

You want a compact rigid box and have checked your finished stack.

Look elsewhere if

You need extra token room, a dice tray, or an assured fit for an untested thick-inner combination.

The buying facts

Manufacturer-stated specifications for the variant reviewed
Rated capacity100 double-sleeved cards in Ultimate Guard sleeves
Other rated capacities120 single-sleeved or 210 unsleeved
Outer dimensions (W × D × H)76 × 75 × 98.5 mm
Reference SKUUGD010689
ConstructionRigid box with secure closure

Specifications: Ultimate Guard Boulder 100+ — Frosted — manufacturer specifications.

Will it fit?

Manufacturer-stated

Ultimate Guard rates 100 double-sleeved cards using its sleeves. Other brands can affect capacity. The external dimensions do not establish how much room remains for tokens or a thicker inner layer.

Compact has a tradeoff

The appeal is a small single-deck package. I would not choose it by subtracting the card width from the outside box width: walls and the closure consume space that the deck cannot use.

Build the stack with the intended inners and playing sleeves first. Include every token or divider that will travel in the main compartment, then check that removal and closing do not require pressure.

Read each capacity independently

The 100, 120, and 210 figures describe different sleeve conditions. They are not interchangeable and are not an invitation to interpolate an exact count for a cross-brand sleeve combination.

For a larger carrier, compare the documented number of Boulders it accepts. A loose-card rating alone is insufficient to calculate the number of closed deck boxes that will fit.

What to compare it with

Gamegenic Bastion 100+ XL

A rigid alternative specifically marketed for thick-inner double-sleeved decks.

Ultimate Guard Sidewinder 100+ Xenoskin Black

A magnetic-cover alternative with a different footprint and inner lining.

Sources & verification

  1. Ultimate Guard Boulder 100+ — Frosted — manufacturer specifications — Manufacturer documentation. Verified 2026-09-26.

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