Mattress materials explained
All about foam
The foam inside a mattress determines how it feels, how well it supports the sleeper, and how long it remains comfortable. Here is what our specifications mean in practical terms.
Comfort
Quality foam cushions the body and responds evenly as the sleeper changes position.
Support
The right density and firmness help prevent the mattress from bottoming out against its base.
Durability
Higher-quality materials retain their shape and comfort better through regular use.
Compare our foam
Mattress specifications
Density describes foam quality and support; IFD describes firmness. They are related, but they are not the same measurement.
| Specification | Gold sofa bed | Platinum sofa bed | RV, marine & truck |
|---|---|---|---|
| DensityPounds per cubic foot | 1.8–1.9 lb.High density | 2.5 lb.Our highest density | 1.8–1.9 lb.High density |
| IFDMeasure of firmness | 48–50High compression | 41High compression | 23–26Medium compression |
| ThicknessFinished mattress depth | 4 or 5 in. | 4 in. | 5 or 8 in.Memory foam options available |
The important terms
Density and firmness, made simple
Foam density
Density measures the weight of polyurethane foam per cubic foot. Denser foam contains less open air space and generally provides stronger, longer-lasting support.
Think: support and durability.
Indentation Force Deflection (IFD)
IFD measures the force needed to compress a foam sample by a specified amount. It is the specification that most directly describes how firm or soft the foam feels.
Think: firmness and feel.
What this means for you
Firmness is not the same as support
- High-density foam can be made soft.
- Lower-density foam can be made firm.
- Density does not describe a foam as “hard” or “soft.”
- Support is the foam’s ability to push back against body weight and resist bottoming out.
Other performance factors
Durability, flex fatigue, and compression set also affect how well foam retains its comfort and shape over time. We account for these characteristics when selecting materials for our mattresses.
For deeper technical information, visit the Polyurethane Foam Association.