Full Mattress in a Box 6 in Full - Medium-Firm Memory Foam

Our review of the Full Mattress in a Box 6 in mattress finds it best suited for sleepers who need a compact, medium-firm memory foam option for a platform bed, daybed or bunk. The single biggest reason to consider this mattress is its balanced medium-firm feel that combines support with pressure relief, making it a good fit for a wide range of body types and sleeping positions. Setup is straightforward: the mattress ships compressed and usually regains shape within 24 to 72 hours, with faster expansion in warmer rooms.

Key Features

• Medium-Firm Support: The 6-7 out of 10 firmness aims to provide spinal support without being overly hard, which helps reduce pressure points for many sleepers.
• Gel-Infused Memory Foam: Gel infusion helps dissipate heat so the mattress retains memory foam comfort while staying cooler through the night.
• Fiberglass-Free FR Inner Cover: The rib fabric cover of 92% cotton and 8% polyester provides a safe flame retardant layer without fiberglass or harsh chemicals.
• CertiPUR-US Certified Foam: All foams are made to CertiPUR-US standards, minimizing off-gassing and supporting indoor air quality upon unpacking.
• Made in the USA: Domestic manufacturing can mean consistent quality control and materials traceability.

Who It's For

This mattress is well suited for people who need a thin, supportive mattress for a platform bed, bunk, or daybed, especially where space is limited and a 6 in thickness is preferred. It is a practical choice for guest rooms, children's bunks, or rental properties where a balance of comfort, safety and value is desired.

Sleepers who need a very plush or thick pillow-top feel, or who require advanced zoned support for specific medical conditions, should look elsewhere; this model is intentionally compact and focuses on general medium-firm support rather than luxury cushioning.

Pros & Cons

Pros

• Comfortable medium-firm feel that suits many body types and supports proper spinal alignment.
• Gel-infused foam reduces heat retention compared with standard memory foam.
• Fiberglass-free inner cover and CertiPUR-US certified foam reduce health concerns related to flame retardants and off-gassing.
• Good fit and value for bunk beds, daybeds and platform frames due to the 6 in thickness.

Cons

• Expansion time can vary; in cold conditions the mattress may take longer than 72 hours to fully expand.
• Some customers report differing perceptions of firmness and thickness, so individual preference may vary.

Specifications

Size	Full
Thickness	6 in
Feel	Medium-firm (6-7 of 10)
Cover material	92% cotton, 8% polyester rib fabric
Foam	Gel-infused memory foam, CertiPUR-US certified
Fire barrier	Fiberglass-free flame retardant inner cover
Manufacture	Made in the USA

Our Verdict

The Full Mattress in a Box 6 in is a sensible, well-made option for anyone needing a compact, medium-firm memory foam mattress for a platform bed, daybed or bunk. With gel-infused foam, a fiberglass-free cotton blend cover, and CertiPUR-US certified materials, it delivers reliable comfort and safety at a practical price, though buyers who want a thicker or much softer feel should consider different models.

Frequently Asked Questions

How long does it take to expand?
Typically 24 to 72 hours, but expansion can take longer in cold delivery conditions or cooler rooms.

Is the mattress safe for indoor air quality?
Yes; the foams are CertiPUR-US certified and the mattress uses a fiberglass-free flame retardant inner cover to reduce health risks.

Will it fit a bunk or daybed?
Yes; the 6 in thickness and full size are designed to fit platform beds, daybeds and many bunk frames.