# Plank Firm (Firm) vs Pure Green Organic Latex (Firm): Firmness, Price, and Construction Compared

Canonical: https://squishmat.com/compare/plank-firm-firm-vs-sleep-on-latex-pure-green-organic-latex-firm · Data refreshed 2026-10-02 · Source: SquishMat

Same feel and similar price — the Pure Green Organic Latex (Firm)'s denser foams give it the durability edge.

## Full spec table

| Spec | Plank Firm (Firm) | Pure Green Organic Latex (Firm) |
| --- | --- | --- |
| Type | Foam | Foam |
| Firmness | 8/10 | 8/10 |
| Height | 10.5" | 9" |
| Queen price | $832 | $799 |
| Price range (all sizes) | $749–$1,532 | $799 |
| Foam densities (lb/ft³, top → bottom) | 1.5 / 2.5 / 1.8 / 1.5 | 4.5 / 4.5 |
| Coil gauge | — | — |
| Coil count (queen) | — | — |
| Cooling | 5/10 | 7/10 |
| Motion isolation | 7/10 | 6/10 |
| Edge support | 5/10 | 6/10 |
| Pressure relief | 8/10 | 7/10 |
| Support | 6/10 | 8/10 |
| Natural materials | 2/10 | 9/10 |
| Notable features | Flippable firm and extra-firm sides, Flat, ultra-firm support surface, Spinal-alignment focus for stomach sleepers, Optional cooling cover | 8" of solid natural Dunlop latex in the firm build, Organic cotton knit cover over wool batting, No polyurethane foam anywhere in the build, GOLS, Oeko-Tex and Greenguard Gold certified |
| Spec source | NapLab | Manufacturer |

## Key differences

- The Pure Green Organic Latex (Firm) uses denser foam (lowest layer 4.5 vs 1.5 lb/ft³) — density is the best single predictor of how long foam lasts before it sags.
- The Pure Green Organic Latex (Firm) scores notably better for sleeping cool (7/10 vs 5/10).

## Who each mattress is for

**Plank Firm (Firm):** The Plank Firm (Firm) has a firm feel suited to stomach sleepers and heavier sleepers who need to keep their hips lifted. Strengths: Excellent pressure relief at the shoulders and hips.

**Pure Green Organic Latex (Firm):** The Pure Green Organic Latex (Firm) has a firm feel suited to stomach sleepers and heavier sleepers who need to keep their hips lifted. Strengths: Strong, even support that keeps the spine aligned; Built largely from natural materials like latex, wool, or cotton.

## FAQ

### Which is firmer, the Plank Firm (Firm) or the Pure Green Organic Latex (Firm)?

They rate the same: both are a 8/10 on the firmness scale, a firm feel suited to stomach sleepers and heavier sleepers who need to keep their hips lifted.

### Which is cheaper, the Plank Firm (Firm) or the Pure Green Organic Latex (Firm)?

The Pure Green Organic Latex (Firm) is cheaper in a queen: $799 versus $832, as of 2026-10-02.

### What is the main construction difference between the Plank Firm (Firm) and the Pure Green Organic Latex (Firm)?

Both are foam builds, but the Pure Green Organic Latex (Firm) uses meaningfully denser foam, which generally predicts better durability. Full per-layer densities are in the table above.

## More

- [Plank Firm (Firm) — full specs](https://squishmat.com/mattresses/plank-firm-firm)
- [Pure Green Organic Latex (Firm) — full specs](https://squishmat.com/mattresses/sleep-on-latex-pure-green-organic-latex-firm)
- [Comparison matrix: every mattress we track](https://squishmat.com/compare)

Free to cite with attribution — link to the canonical page. Where a datapoint traces to a third-party teardown, please credit the original measurer too (sources are cited per bed on https://squishmat.com/mattress-database).