Many mattress companies these days are advertising latex with five, even seven “zones” of varying densities. Here, we consider what latex zones are and are not, and why they are mostly irrelevant to sleep comfort.
When a layer of latex is made without zones, it is intended to feel consistent from side to side and head to foot. There’s always minor variability, but latex without zoning doesn’t vary much within each piece.
To make latex with multiple zones, a manufacturer varies the pin pattern in the mold, usually from head to foot (not side to side), and usually on the top or bottom of the mold. The mold has pins or steam pegs that stick up from the bottom, and the latex is poured around the pins. The holes in natural latex show where the pins were.
Where more pins are located, there are more holes and less latex, which creates a softer feel. With fewer pins, more latex is distributed, producing a firmer feel. The difference in density and ILD, or indentation load deflection, can be scientifically measured.
The question is: even though the zones are visible, do they really improve the sleeping surface? Here are three issues to consider.
Height of the sleeper and zone dimensions
How tall are you and how tall is your partner? It’s uncommon for partners to be exactly the same height; and if you aren’t the same height as your partner, the different zones in your mattress would meet your bodies in different areas.
For example, the shoulders and hips of someone who is 5’2” would lie on certain zones, and the shoulders and hips of their 6’ 1” partner would rest on different zones.
Actual differences in zones
We have examined zoned latex made by multiple manufacturers. In the same sheet of latex, there’s normally little difference from a firmer zone to a softer zone. Often one zone feels no different from another. Differences in firmness will vary more from one piece to another than they do from zone to zone in the same piece.
Support versus pressure relief
How many zones does your body have, and how should those areas feel?
Most of us are heavier in the shoulders and hips, so it makes sense that we need more support in the shoulders and hips in order to stay aligned.
True enough, but some people need more pressure relief in those areas because that’s where the most pressure is created. You can’t have both support and pressure relief in the exact same spot.
Many advertisers may tell you that their mattress offers both support and pressure relief; but the truth is more nuanced: the more supportive foam is in any particular area, the less pressure relieving it is.