The Plank Firm from Plank Mattress is a foam mattress with a firm feel suited to stomach sleepers and heavier sleepers who need to keep their hips lifted.
Inside the Plank Firm
Plank Firm
10.5" tall
Plank Mattress · Foam · Firmness 10/10
Hover or tap a layer to slide it out
Layer breakdown
Polyfoam comfort layer
0.75″ thick · 1.5 lb/ft³ density
1.5 lb/ft³ foam runs light, but at 0.75″ it's a surface quilt — too thin to drag durability down.
Polyfoam transition layer
2″ thick · 2.5 lb/ft³ density
Measured at 2.5 lb/ft³ — high-density foam like this resists softening and body impressions, one of the strongest longevity signals in a build.
Polyfoam transition layer
7″ thick · 1.8 lb/ft³ density
Measured at 1.8 lb/ft³ — solid polyfoam for average-weight sleepers, though heavier (200 lb+) sleepers would want closer to 2 lb/ft³ here.
Polyfoam support core
0.75″ thick · 1.5 lb/ft³ density
Measured at 1.5 lb/ft³ — solid polyfoam for average-weight sleepers, though heavier (200 lb+) sleepers would want closer to 1.8 lb/ft³ here.
Hover or tap a layer to see what it means for comfort and durability.
Total height10.5"
What it does well
Excellent pressure relief at the shoulders and hips
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