Natural sheets or a new greenwashing low? Bamboo, Eucalyptus, Beech, Sandalwood, 'Plant-based', Lyocell and Tencel®

Most retailers and consumers think Bamboo and other plant-based bedding is natural and 100% organic. But this claim doesn't match the chemistry, or US-based labelling laws. Before you buy, here’s the clear, no-fluff guide to what these fabrics are, and what they're like to sleep in.

What are we talking about?

It's time to talk about bedding made from bamboo, eucalyptus, beech, sandalwood, lyocell, Tencel®, modal, viscose, cellulose, regenerated, reconstituted, extrusion process or any other plant-based derivative. The internet is filled with retailers bombarding us with claims like 100% natural, 100% organic and 100% pure bamboo...

And if they don't outright say 100% natural, they use terms like eco-friendly, environmentally sound, sustainable and plant-based - often with green imagery.

OK, so these sheets are definitely natural - right?

How are fibres classified?

It's time for a quick textile lesson. Chapter 1 of Textiles and Fashion: Materials, Design and Technology outlines two broad categories for textile fibres; Natural and man-made.

Natural fibres

Natural fibres occur naturally and despite manufacturing, the fibre is still present in the finished article. Natural fibres include; wool, cotton, linen, hemp and silk (the real stuff, not reconstituted silk).

Human-made fibres

Human-made fibres aren't naturally occurring, and are created using a manufacturing process. Examples include; polyester, rayon and carbon fibre.

So what are bamboo fibres?

Bamboo, eucalyptus and other 'plant-based' bedding is in reality, Rayon. A human-made fibre. Yes, everything old is new again. There are many steps, and the steps vary depending on the type of rayon. But broadly speaking, plant matter (like bamboo) is chemically dissolved and the resulting liquid or 'dope' is pushed through tiny holes to create a yarn.

From Textiles & Fashion, materials, design and technology...

Calling rayon 'bamboo' is in itself, a greenwashing win

To make rayon, the plant (often bamboo) is chemically dissolved to such a degree that it no longer exists in the final bedding. Good House Keeping recently proved this with lab testing, see link at the very bottom - highly recommended. When the wood used is completely dissolved, simply calling rayon 'bamboo' is a huge greenwashing win.

You can also tell it's not natural because of how shiny it looks, and how smooth it feels. Here are some close-ups, see how smooth lyocell rayon is? Natural fibres aren't this smooth or shiny.

So there's no question bamboo/lyocell/viscose/modal rayon isn't natural, it's human-made. But this begs the question, how do brands get away with this?

Enter The US Federal Trade Commission

Like many bedding scandals, this is old news overseas. Since 2009, The US Federal Trade Commission has been warning, suing and fining retailers over greenwashing rayon into bamboo. Some of the brands involved include; Bed Bath & Beyond, JC Penny, Nordstrom, Macys, Kohl, Amazon, Sears and more.

Sound familiar? Many of these brands were caught up in the fake Egyptian cotton scandal of 2017 and many spent decades dressing-up mediocre cotton in high thread counts (see Bed Bath & Beyond's 1000TC lawsuit).

But back to rayon. Under the FTCs Textile Fiber Products Identification Act and the Textile Fiber Rule (links at end), Rayon products are allowed to state the plant source but must be up-front about the fibre type, in this case, modal, viscose or lyocell which are all different forms of rayon. But because the FTC is a United States Government organisation, these rules don't extend to our part of the world.

But what about mechanical bamboo fibre?

Some blogs and retailers mention a mechanical bamboo fibre. As far as we can tell, the intensive process used to create mechanical bamboo has to date, been too costly to replicate at commercial scale. And by all accounts, the resulting fabric is also fairly rough - it's wood after all. Also, the references we've found talk about the theory of how bamboo could used as a sustainable fibre, not finished sheets currently for sale.

Although we've never seen mechanical bamboo sheets being sold, a quick way to check at home would be to look at the finished fabric. If it's shiny and silky/drapey/soft, it's not mechanical bamboo. See the close-up image comparing lyocell rayon fibre with natural fibres above. Note how smooth human-made fibres are? That translates into the trademark silky feel and shinier look of rayon.

Natural fibres don't look or feel like this, they're too rough.

As a side note, it's a similar story with all the cost-effective silk seen everywhere. While real silk is shinier than cotton, it's nowhere near as shiny as the much cheaper, regenerated, reconstituted, or extrusion process silk, that 99% of retailers seem to sell. Even a $180 NZD pillowcase (just one) we sleep-tested from a well-known global retailer, was using an extrusion process similar to rayon. If you want real silk, look for cut fibre silk, but expect to pay €140 per pillowcase or more.

Bamboo isn't natural but it's still great for hot sleepers - right?

While everyone believing a lie isn't great, at least rayon bedding helps hot sleepers - right?

Well, Christina is menopausal and like most men, I've always slept hot. To find bedding that balanced our sleep temperature, we've spent almost 15 years sleep-testing bedding in a temperature controlled room (our bedroom).

As a company, we can make and sell any kind of sheet - we've already changed our name once to better reflect the sheets we sell. The only reason we sell the sheets we do, is because after years of sleep-testing, these sheets offered the best temperature regulation. And no, we're not pretending our bedroom is a sleep lab, but a heat pump set to 18° is better than the way most people judge sheet heat at home.

And the lyocell sheets we tested? They were almost as hot as the poly/cotton sheets found in most hotels. So what about the claims?

'...designed for better sleep through temperature regulation...'
'...silk-like softness and breathability...'
'...designed to keep you cool...'
'...cooling and breathable for hot sleepers...'
'...naturally breathable...'
'...more cool and more breathable...'

Or FAQs like...

'Q. Does it actually have cooling properties? A. Yes, bamboo bedsheets are naturally cooling due to their breathable and moisture-wicking properties. They help regulate body temperature by drawing heat and moisture away from your skin, making them ideal for hot sleepers.'

In our experience, these 'cooling' statements betray a home truth about retailers; They don't sleep-test their sheets or if they do, they aren't menopausal or hot sleepers.

But moisture-wicking is science - right?

If the internet is to be believed, it's scientifically proven that; '...Bamboo fabric is known for its excellent moisture-wicking properties... keeping you cool and dry.' Even AI says it, so it must be true!

But after sleep-testing rayon, we were confused. We experienced the opposite. Rayon was nothing like cotton to sleep in. It was like it repelled moisture, leaving us clammy and sweaty - truly, a horrible night's sleep. But if science says it has excellent moisture-wicking properties, why did we experience the opposite?

It might be that rayon was hotter to sleep in, making us more sweaty. Or maybe cotton also has good moisture-wicking properties - a bit like how rayon is promoted as hypoallergenic. Well, so is cotton.

If you find rayon cooler than cotton, it's probably due to the recipe of your cotton sheets - cotton can be woven to trap heat. But if woven for airflow, it balances temperature fluctuations beautifully.

Does moisture-wicking equal sleep comfort?

We regularly travel to Heimtextil, the largest home textile fair in the world. In 2025, we saw a new rayon/cotton blend based on lyocell from Eastman (of Kodak fame) called Naia. It seems to be a blend of about 40% lyocell, with recycled fibres, although they never emailed their follow-up brochure so we can't be sure.

Their presentation contained a chart which visualised data from a book called 'Synthetic Fibers' by Franz Fourne. Here's a reproduction of that data which compares the moisture absorption of various fibres...

Notice that yellow 'comfort zone' on the chart? It seems that while moisture-wicking can be defined and tested scientifically, there's a comfort zone which better explains what a fabric might feel like to sleep in. You can see cotton falls squarely into that comfort zone, but rayon falls well outside it.

While it's true that rayon has high absorption, it's not as comfortable to sleep in compared to cotton (rayon is also hotter in our experience). We don't pretend to understand the difference between the science and the sleep experience (if you do, drop us an email). But we did experience what this chart seems to show; that rayon isn't as comfortable to sleep in as natural fibres.

If any rayon derivative was as comfortable as the sheets we offer, we'd use it, recommend it, and sell it ourselves.

OK, but lyocell is different - right?

In recent years, we've seen brands and heard from consumers, claiming lyocell is different because its 100% natural - even NZ companies. So where did lyocell come from?

A variety of researchers (some from Eastman Kodak) discovered more eco-friendly solvents that could be used to dissolve the plants used to create rayon. From 1966 to 1979, they explored ways to commercialise it, but it wasn't until 1982, when a UK-based R&D team developed a commercial way to produce lyocell. This culminated in 1992 with the Tencel® trademark.

The Tencel® trademark was eventually sold to an Austrian company, Lanzing, who own the rights today. While lyocell uses more eco-friendly solvents to dissolve wood, the resulting fabric is still rayon. Therefore, lyocell is still human-made, it's not natural.

So what does Lanzing say?

Note: In the next section, we share an experience and professional conversation. At the time, we were genuinely curious about Tencel® as we didn’t understand it. We're including it here because we'd encountered New Zealanders at home shows, and on Facebook, who believed both Tencel® and lyocell, were completely natural. We wanted to understand these fibres directly from the people manufacturing it.

We're not journalists and haven’t contacted Lenzing for a response, which is unfair. We don’t hold them responsible for how retailers market Tencel® or rayon, and found them professional, straight-up, and quick to correct any misinformation. We don’t believe their representatives were involved in anything suspicious and neither should you. If you work for Lenzing and wish to respond, please send us an email.

At Heimtextil 2025, we talked to Lanzing, the Austrian company who owns the trade marked version of lyocell, called Tencel®. Initially, a junior, Chinese-based representative told us Tencel® is natural.

But a more senior, European-based representative, told us; "No, it's man-made". She then correctly explained the difference between natural and man-made fibres, and we had a 20 minute conversation about the pros and cons of Tencel® - yes, we're nerds for this stuff!

We wouldn't read too much into the junior representative's initial characterisation as natural, this was a lack of knowledge and the senior representative was quick to set everyone straight.

Fact: lyocell and Tencel® aren't natural fibres

If the company selling the trade marked version of lyocell says it's "man-made", then lyocell and Tencel® aren't natural. Lyocell and Tencel® are also clearly outlined as a rayon derivative in the rayon section of Textiles and Fashion: Materials, Design and Technology. Leaving no doubt, lyocell and Tencel® aren't natural.

But Tencel® is more sustainable - right?

It's definitely more sustainable than other forms of rayon. And when you buy the Tencel® brand, you're also getting a guarantee that the bamboo is sustainably sourced. But If you're not buying Tencel®, anything goes - truly, you have been warned!

However, is Tencel® as sustainable as it's claimed? We haven't been able to find cradle-to-grave sustainability information on the full product lifecycle of sheets (if this info exists, drop us an email). So brands often promote a small slice of the overall sustainability pie. For example, consider this graph from a Tencel® brochure. It tracks the environmental impact of producing various fibres...

Look at the far right - Tencel® has the lowest impact. But look at the last sentence under the graph;

"However, this figure only shows impacts from cradle to fibre production gate."

In other words, this graph only tracks the environmental impact of growing bamboo, and doesn't include the impact of processing wood into a fabric.

Why does his matter?

In general, the less cotton-like a raw fibre is, the more processing is required to turn it into something modern humans want to sleep in - especially textiles used close to the skin (like sheets).

Linen and hemp are great examples. Compared to cotton, they require more processing to turn into a softer fabric people want to sleep in, increasing their environmental impact. And before humans want to sleep in wood? Well, wood requires a full chemical break-down to completely dissolve it.

So yes, if you take a small slice of the overall picture, you can say: "bamboo good, cotton bad". If only things were that simple.

The pot calling the kettle black

As a company currently selling cotton bedding, you should rightly point out the endless lies around cotton. Things like the thread count myth, fake Egyptian cotton, organic cotton being better etc.

Also, it's a fact that fast fashion uses huge amounts of cheap cotton, which consumes large amounts of land, drinking water, and releases enormous amounts of pesticides. And because nothing is meant to last (fast fashion often releases new collections every 6-8 weeks) demand for this cotton is off the charts.

We don't buy this type of cotton (for many reasons) which is why our sheets aren't cheap. But that bamboo cultivation graph partly illustrates why we currently stick with cotton. If rayon sheets are more sustainable than cotton, why hide the full picture?

So we're anti-sustainability then?

We applaud companies looking for, or creating more sustainable fibres. We monitor much needed progress and try to talk face-to-face to those leading the charge. But with so much on the line, why obfuscate the truth?

Corporate malfeasance breaks trust and it seems nobody trusts anyone anymore. And we get it. We trust almost no one in the textile industry, we research anything we're told. Frankly, it's exhausting.

This is why our website also doesn't contain fluffy statements about sustainability and ethical sources. Each time we look into the latest green trend, we come away with more questions than answers - like that bamboo cultivation graph.

And frankly, we don't fully understand the Oeko-Tex certification our team in Portugal have. In general, we're suspicious of the industry certifying itself. But unlike other programmes, at least the Oeko-Tex certification modifies practices.

The Better Cotton Initiative for example, seems more like a credits trading scheme, which can allow companies to buy their way out of certain practices. At least that's how our team characterised BCI after they looked into the certification for themselves.

But why don't you sell organic cotton?

We also don't currently offer organic cotton for similar reasons. We don't fully understand how anyone can claim it's more sustainable, as it seems to deliver about 40% of the yield for the same land-use, so uses much more land.

And the lower yield also means organic cotton consumes much more drinking water - in hot climates where drinking water is precious.

We also talked to a gentleman from the Hawkes Bay who sprayed organic cotton in Australia for a living. He said he had to wear a full hazmat suit when using organic pesticides and he still got sick. It would seem there are plenty of natural compounds that are highly toxic to humans. And unlike organic food, there's no evidence organic cotton is better. None of the longer-lasting, top-grade cottons are organic for example.

But even if organic cotton was better, we don't understand how anyone tests finished textiles to ensure they actually contain organic cotton.

Especially if you're buying organic cotton from countries with a proven track record of lying like China and India. For example, our European teams have clients who were told by Chinese manufacturers, that a GOTS certified logo could simply be added to their packaging! Which isn't that surprising if you've been tracking the fake Egyptian cotton scandal. BTW organic cotton is the subject of a long-overdue, future article. But be warned, it's not simple.

The highest quality for the cheapest price

We stick to selling the highest quality cotton for the cheapest price we can. It lasts longer than cheaper cotton which reduces the churn of resources.

And unlike new "100% natural, pure, organic bamboo", cotton marketing is not based on a fundamental lie.

Also people want to sleep in cotton, so are less likely to throw it out. According to the textile school at the University of Otago, kiwis toss an estimated 37kg of home textiles per person, per year.

It's also one of the reasons why we sell white sheets. Colour is less sustainable because of the resources used to dye fabrics (fabric dying in India and China looks like a horror show).

But worse, people tend to replace colour more often because the colour looks tatty, or because the colour/pattern has simply gone out of fashion.

Yes, there's an environmental cost to a cap of chlorine bleach every few years but to us, the impact seems smaller than buying new products, more often. So where does that leave us?

Is our stance on sustainability perfect?

Nope. But each time we look into sustainability claims and ethical best practices, we come away with more questions.

And we find it impossible to blindly parrot claims like other brands seem to. Of course, we recognise they might know something we don't, but not according to the science, or the industry people we talk to.

If you love rayon, who cares

If you love Rayon and it works for you, who cares what anyone says - enjoy it. Just don't think it's natural. Or do, everyone else does!

What we sleep on instead

Christina is menopausal, and like most men, I've always slept hot. The only reason we sell the sheets we sell, is because after 15 years sleep testing sheets in a temperature controlled bedroom, these sheets did the best job of regulating temperature.

But they're not a miracle cure, sleep is complex. You can't sleep in PJs or other bed clothes and expect temperature regulating sheets like ours to work.

Likewise with puffy duvets or any kind of human-made fibre like poly/cotton or rayon - or even rayon blends sold as bamboo/cotton. Avoid! And if they work for you, great. But that just means you don't struggle with temperature as much as we do.

Natural fibres like cotton or linen, woven for airflow work best but we even found linen hotter than our sheets - thickness for any reason is always hotter. This also means you have to be able to see through the sheet. The trick? Find finer sheets made from decent cotton, yarn and weaving so you still get decent wear. Hence The Hotel Sheet.

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Natural sheets or a new greenwashing low? Bamboo, Eucalyptus, Beech, Sandalwood, 'Plant-based', Lyocell and Tencel®

What are we talking about?