Best For
- Very firm feel—flippable sides (8 or 9 out of 10)
- Back or stomach sleepers, as well as heavier sleepers
- Extremely high levels of bounce (preferential factor)
Considerations
- Pressure relief could be a struggle for lightweight sleepers or side sleepers
- Higher levels of motion transfer 14.61 m/s², almost 2X the average
Our Verdict
The Plank Firm natural mattress is a 10.5″ natural latex hybrid with flippable firmness levels. One side is an 8 out of 10 (firm) and the other side is a 9 out of 10 (extra firm). It uses a natural 100% Talalay latex comfort layer with a pocketed coil support base.
This mattress is all about the firm / extra firm feel. If your body likes that feel best then the few cons we experienced probably won’t be major factors for you. In addition, this is one of the first natural mattresses we’ve tested that offers the extra firm feel.
The mattress offers very minimal sinkage and very high bounce. This makes the surface easy to move around on.
In our performance tests, the Plank Firm Natural earned an overall score of 8.55. This is just about average and it ranks within the bottom 45% of all mattresses tested to date. However, it’s considerably lower than the average latex hybrid we test. High motion transfer and a long off-gassing duration is what brought the score down the most.
Its price ($1,599) is just about average for what you can expect to pay for a latex hybrid (average being $1,533.39). All things considered, the Plank Firm Natural is still a decent deal, especially for those who need or prefer a firmer feel.
Type: Latex Hybrid
Firmness: Firm (8) or Extra Firm (9)
Best For: Back And Stomach, Heavy Weights
In This Review
Performance Tests | Firmness | Support & Sleeping Positions | Design | Materials | Comparisons | FAQs
The Plank Firm Natural is a flippable mattress with a firm and an extra firm side. Our measurements, tests, and scores are based on our experience on the firm side of the mattress.
Performance Tests
At NapLab, we put each mattress to the test.
We test 10 different factors that impact the performance, comfort, and value of the mattress. We then take the results of that test and compare to every mattress we’ve tested to date.
Check out the full performance table below to see how this mattress ranks:
| Factor | Plank Firm Natural | Average |
|---|---|---|
| Overall Score | 8.55 | 8.53 |
| Price (Queen) | $1,599 | $1,533 (Latex Hybrid only) |
| Cooling – Score | 9.0 | 8.6 |
| Sinkage – Depth | 1.53″ | 2.16″ |
| Sinkage – Feel | Very Minimal | Moderate |
| Motion Transfer – Score | 5.7 | 8.2 |
| Motion Transfer – Acceleration | 14.61 m/s² | 8.75 m/s² |
| Response Time – Score | 10 | 8.8 |
| Response Time – Mostly Recovered | 0.2 sec. | 0.4 sec. |
| Response Time – Fully Recovered | 0.3 sec. | 1.0 sec. |
| Bounce – Height | 12.24″ | 9.26″ |
| Bounce – Feel | Very High | Moderate |
| Edge Support – Score | 9.5 | 8.6 |
| Edge Support – Sitting | 2.75″ | 4.04″ |
| Edge Support – Lying | Excellent | Good |
| Sex – Score | 9.8 | 8.3 |
| Pressure Relief – Score | 8.0 | 8.6 |
| Comfort Layer Thickness | 2.3″ | 4.2″ |
| Mattress Thickness | 10.5″ | 12.1″ |
| Off-Gassing – Score | 7.8 | 8.2 |
| Off-Gassing – Smell | Strong | Strong |
| Off-Gassing – Days | 8 days | 7 days |
| Company – Score | 9.7 | 8.6 |
| Trial | 120 nights | 178 nights |
| Warranty | Lifetime | 29% have lifetime warranties, average of other 71% of mattresses is 13 years |
How is the Plank Different?
The Plank Firm Natural is currently the only natural latex hybrid in the Plank collection. It is extremely firm compared to most other mattresses, which put it in a unique position.
The overall performance score for the Plank Firm Natural is 8.55, which is right around the average score of 8.57, based on 270 mattresses tested to date. The price of the mattress at $1,599 is also just under the average for a latex hybrid, based on the 24 we’ve tested so far.
Advantages
The Plank Firm Natural performs well in most categories. But categories like cooling, response time, and edge support were particularly fantastic. If those are areas that you prioritize and you love the feel of latex, this is a great choice for you.
Neutral Factors
Factors that are more preferential like sinkage and bounce were both quite a bit different than average. Our sinkage measurement showed that it has 29% more sinkage than the average mattress.
However, bounce was 28% higher than average, and that puts it just more than my preferred range for most sleepers.
Disadvantages
One of the bigger drawbacks of the Plank Firm Natural is its high motion transfer (68% higher than average). Due to its firmness and other design elements, I would say most sleepers are at some risk of feeling movements from across the mattress. Pressure relief was good, but had plenty of room for improvement.
Cooling Test
Cooling performance on the Plank Firm Natural is excellent. During our tests, I felt no significant level of heat retention around my body.
Baseline Temp.
66.6° F
Max Temp.
86.0° F
Ending Temp.
71.7° F
The latex hybrid composition is a proven design that has been used for decades, in large part due to its excellent cooling performance. Latex as a material type doesn’t retain heat and breathes well.
Max Temp.
Ending Temp
- Baseline Temperature – the temperature of the mattress before anyone lies on it
- Maximum Temperature (0 minute) – the temperature of the mattress after lying on it for 15 minutes
- Ending Temperature (5 minute) – the temperature of the mattress after being lied upon and having no one on it for 5 minutes
In addition, the layer of support coils provides ample airflow, further improving cooling. Lastly, the firmer feel creates more of a floating feel, preventing the mattress from overly enveloping sleepers.
All three of these factors combine to help keep sleepers cooler. Looking at our objective data, we measured a maximum surface level temperature 86.0° F.
From minutes 0 to 1 the temperature was reduced by 7.6°, with a 14.3° reduction from minutes 0 to 5.
The minute-by-minute temperature reduction on the Plank was particularly impressive.
Heat Dissipation Over Time
Looking at our objective data alongside my subjective experience, I am pleased with the cooling performance of the Plank Firm Natural.
Sinkage Test
The Plank Firm Natural has a very minimal level of sinkage. In our tests, we measured 1.53” of pressure point sinkage compression. This is 0.62” less sinkage than the average of 2.15” (based on all of our tests to date).
Sinkage Depth
1.53″
Sinkage Feel
Very Minimal
The level of sinkage is documented in the image below.
With this minimal sinkage depth, the Plank Firm Natural creates a notable “floating on top” of the mattress feel, as opposed to lying “in” the mattress. It has a very restrained and generalized contour around the body, which is typical of latex hybrids.
And yet, it’s even more restrained due to the firmer feel. This type of sinkage dynamic is neither good nor bad, but it is certainly more extreme. You really need to have a strong desire for minimal sinkage to be comfortable on this mattress.
Motion Transfer Test
The Plank Firm Natural has a very high level of motion transfer. In our tests, we measured a total acceleration range of 14.61 m/s². This is 67% more more motion transfer than the average of 8.79 m/s².
That said, the higher motion transfer was expected. Firmer mattresses create more motion because the firmer feel causes the mattress to rebound energy more quickly, as opposed to soaking and absorbing.
The level of motion transfer is documented in the video below.
Max. Acceleration
6.55 m/s²
Min. Acceleration
-8.06 m/s²
Accel. Range
14.61 m/s²
In addition, latex hybrids create higher motion due to the highly responsive and springy nature of latex and the high bounce of coils.
Looking at our motion transfer chart, which visualizes our accelerometer data, we see high motion until 1.00 seconds. It’s only after 1.00 seconds that motion returns to near-zero levels.
Both the motion intensity and motion duration are far from great. Sleepers who are more sensitive to motion transfer should carefully consider whether a latex hybrid is the right choice, especially those who prefer / need a firm mattress.
Response Test
The Plank Firm Natural has extremely fast responsiveness. In our tests, we measured a mostly recovered response time of 0.2 seconds and a fully recovered response time of 0.3 seconds.
Both of these measurements are notably faster than the average of 0.45 (mostly recovered) and 0.90 seconds (fully recovered).
Mostly Recovered
0.2 sec.
Complete Recovery
0.3 sec.
The level of responsiveness is documented in the video below.
The latex hybrid design drives all of the performance here, as does the firm feel. Latex as a material type is incredibly responsive and effectively instant.
The coils further aid in the spring back, while the firm feel reduces the depth in which materials need to recover. These factors work together to create a near-instantaneous material response.
Faster response helps improve ease of movement, prevent any type of a stuck feeling, and enhances sex.
Bounce Test
The Plank Firm Natural has an extremely high level of bounce. In our tests, we measured 12.24” of total bounce height. This is 2.71” more bounce than the average of 9.53”.
Max. Depth
5.05″
Max. Rebound
7.19″
Total Bounce
12.24″
In general, I like to see 8-12” of total bounce height. It’s a sort of sweet spot that maximizes benefits while minimizing downsides.
Plank is a bit beyond my ideal range, but only slightly. As with response, the material types and design are driving much of the bounce. Both latex and coils have a high degree of bounce.
Max. Sinkage Depth
Max Bounce Height
In addition, a firmer feel (especially with these materials) creates a higher degree of bounce. More bounce isn’t necessarily better or worse. However, sleepers should absolutely be prepared for the higher bounce and everything that comes with it.
The level of bounce is also documented in the video below.
Edge Support Test
The Plank Firm Natural has excellent edge support for lying and outstanding support for sitting. In our sitting edge support tests, we measured a sitting sinkage compression of 2.75”. This is 1.29” less sinkage than the average of 4.04”.
Max Sinkage
2.75″
Lying Support
Excellent
When it comes to sitting sinkage, less is better. In general, I like to see 4.0” of sitting edge compression or less. Plank Firm Natural easily exceeded my benchmark.
Even when sitting directly on the edge of the mattress I felt incredibly well-supported.
The level of edge support while seated is documented in the images below.
Sitting, 140 lbs.
Sitting, 200 lbs.
Lying edge support is equally as impressive. When lying directly on the edge of the mattress I felt fully supported in all sleeping positions.
The level of edge support while lying is documented in the images below.
Lying on Edge, 140 lbs.
Lying on Edge, 200 lbs.
The firmer feel creates incredibly robust support even at the very edge of the mattress.
Sex Test
The Plank Firm Natural has outstanding sex performance.
We use the scores from all factors, plugged into the formula above, to derive a sex score for each mattress.
| Sex Factor | Factor Weight | Score | Rating |
|---|---|---|---|
| Bounce | 65% | 10 | Extremely High |
| Edge Support | 20% | 10 | Outstanding |
| Noise | 5% | 8.0 | Moderate |
| Pressure Relief | 5% | 8.0 | Good |
| Cooling | 5% | 9.0 | Excellent |
Overall, this is a great score. Despite its firmness, this mattress generates big bounce and great edge support. These are two of the most important factors we consider.
Still, the firmness could still be an issue for some sleepers. This kind of firmness can pose pressure relief issues for lighter sleepers, as the extra firm side is not that far from the feeling of having sex right on the floor.
Pressure Relief Test
Pressure relief on the Plank Firm Natural is more of a unique story. This is the type of mattress that creates ample support through a firmer feel.
When the body is fully supported, pressure will be relieved (for some) relative to other mattresses that create improper support. That said, this is a firm and very firm mattress (depending on the side you use).
Comfort Layer
2.3″
Support Layer
8.3″
It’s not the type of mattress that’s going to cradle the body, creating pressure relief through softness, body contouring, or hugging foams. As such, pressure relief is more atypical on this mattress.
With only 2.25” of comfort material on each side, the mattress doesn’t create comfort through pressure relief and soft materials on top.
Instead, it aims to create pressure relief for those sleepers who desperately need the increase in firmness to be adequately supported. Provided that you are indeed that type of sleeper, I expect you’ll find pressure relief to be sufficient.
However, many sleepers, especially lighter weight and side sleepers, will find the pressure relief lacking due to the firmer feel and minimal comfort layer thickness.
Off-Gassing Test
Off-gassing on the Plank Firm Natural fair, but not particularly good.
The smell was strong right out of the box. It smelled for 8 days, which is only one day longer than the average of 7 days.
Initial Smell Strength
Strong
Off-Gassing Period
8 days
The smell was primarily just that of natural latex—a typical rubbery smell.
This isn’t that uncommon for natural latex mattresses and is different from other offensive smells that you may encounter with a memory / poly foam mattress.
Company
Plank is a sub-brand of Brooklyn Bedding and provides a 120-night trial period and a lifetime warranty with all of their mattresses. Shipping is free straight to your door.
| Company Factor | Factor Weight | Score | Data |
|---|---|---|---|
| Trial Period | 15% | 8.0 | 120 nights |
| Warranty | 10% | 10 | Lifetime |
| Shipping | 5% | 10 | $0 |
| Returns | 20% | 10 | $0 |
| Trust | 50% | 10 | Outstanding |
| Country of Origin | 0% | USA |
How firm is the Plank Firm Natural?
The Plank Firm Natural is a flippable mattress with firm feels on both sides. One side is an 8 out of 10, where 10 is the most firm. The opposite side is even firmer, a 9 out of 10.
This is very firm and would be unsuitable for most lightweight sleepers as well as side sleepers of any weight.
Plank Firm Side
Plank Extra Firm Side
Support & Sleeping Positions
Support on the Plank Firm Natural is excellent. The firm and very firm feel creates more than enough support for all body types. During our tests and in all sleeping positions I felt fully supported.
That said, the level of firmness and the type of support on this mattress will not be appropriate for all sleepers. The firm / extra firm feel is best suited to the needs of heavier-weighted bodies and stomach / back sleepers.
I would strongly advise against this mattress for side sleepers. Side sleepers need more softness and sinkage to allow the spine to achieve a neutral alignment.
The table below shows sleepers who may be right for the firm side of the Plank Firm Natural (8 out of 10).
| Sleeper Weight | Stomach Sleepers | Side Sleepers | Back Sleepers |
|---|---|---|---|
| Under 150 lbs. | Maybe | No | Maybe |
| 150-250 lbs. | Maybe | No | Maybe |
| 250-300 lbs. | Yes | Maybe | Yes |
| Sleeper Weight | Stomach Sleepers | Side Sleepers | Back Sleepers |
|---|---|---|---|
| Under 150 lbs. | Maybe | No | Maybe |
| 150-250 lbs. | Maybe | No | Maybe |
| 250-300 lbs. | Maybe | No | Maybe |
Design
The Plank Firm Natural is a latex hybrid mattress that combines perforated natural latex and a support coil base. It is a flippable mattress with a firm feel on both sides of the mattress.
Type
Latex Hybrid
Thickness
10.5″
Firmness
8 or 9
Materials
As a flippable mattress, there is a quilted cover on both sides of this mattress. An inside look at the Plank Firm Natural reveals five different layers in total including:
- 0.75″ quilted cover
- 1.5″ natural latex
- 6.0″ pocketed coils
- 1.5″ natural latex
- 0.75″ quilted cover
The Cover
The quilted cover both on the top and bottom is made of 100% organic cotton and is GOTS certified. The edges are accented with a sage cord binding and breathable sides.
The Comfort Layer
Whether you’re looking at the Firm Side or the Extra Firm side, the comfort layer on both is a 1.5″ thick Talalay latex (although slightly different firmnesses between the two sides).
The comfort layer is perforated, which promotes breathability as well as the overall response of the foam.
The Support Layer
Depending on what side of the mattress you’re on, the support layer is the same. It’s a 6.0″ pocketed coil system that provides support for the latex foam comfort layer above.
One discrepancy I noticed between the mattress we received and the one advertised on Plank’s website is the thickness of the coil support.
On our mattress, it is very clearly a 6.0″ layer, but the Plank website states that it will be an 8.0″ layer of support coils. This would give the Plank Natural an overall thickness of 12.5″, but the mattress we tested is only 10.5″ thick.
Not sure if this is a fluke with just the mattress that was mailed to us or a typo on Plank’s website.
Product Evolution
The Plank Firm Natural mattress was released in March 2023. Since its release, there have been no changes to the mattress. As the product grows and develops, I will update this section to reflect any changes.
In early 2025, all Brooklyn Bedding mattresses, including sub-brands like Plank, had their warranties updated from 10 years to lifetime.
Other Mattresses to Consider
Not sure if the Plank Firm Natural is right for you? Here are three other top-rated latex hybrid mattresses you may want to consider.
For Softness
Birch
Slightly Firm (7 out of 10)
The Birch is another great option for a latex hybrid. It has a 2.0″ natural latex comfort layer and coil base. This mattress is softer than the Plank Firm and could be a good option for sleepers looking for something less firm.
For Motion Transfer
Awara Natural
Overall Score: 9.26
The Awara natural latex hybrid is a 10″ thick mattress with extremely low motion transfer levels—3.72 m/s² accelerometer. The Plank Firm Natural is 14.61 m/s² (average is 7.77 m/s²). Awara has 75% less motion transfer than Plank. Note: It also has a softer firmness (6 out of 10).
For Side Sleepers
EcoSleep Hybrid Luxe
12″ Thick Mattress
The EcoSleep Hybrid Luxe, a sub-brand within Brooklyn Bedding, uses a 3.0″ layer of latex foam on top which provides better pressure relief. This would be especially beneficial for lighter sleepers as well as side sleepers.
Frequently Asked Questions
Still have questions? Check out some of the top FAQs on the Plank Firm Natural mattress below and get the answers you’re looking for.
Here are the current prices, with any sales or promotions reflected below:
Twin: $1049
Twin XL: $1199
Full: $1398
Queen: $1599
King: $1998
Cal. King: $1998
*Note: Sales prices are subject to change without notice or warning.
The Plank Firm Natural is made of perforated Talalay latex and a pocketed coil base, all wrapped within a 0.75″ quilted cover on both sides.
Plank is owned by Brooklyn Bedding, which is owned by 3Z. 3Z is a parent company that aowns several mattress brands, including Brooklyn Bedding Helix, Nolah, and Leesa, among others.
