Thread count explained: why 600 TC is often just 300 real threads

"600 TC", "800 TC", "1000 threads" – the numbers on bed linen packaging seem to get bigger every year. Many buyers therefore assume: the higher the thread count, the better the bed linen. It isn't quite that simple. In this guide, we explain what the thread count (TC for short) actually measures, how 300 threads on paper can become 600 – and what you should look for instead.

What thread count actually measures

A bed linen fabric consists of two thread systems: the warp threads, which run lengthwise, and the weft threads, which are woven in crosswise. The thread count counts how many of these threads together lie within an area of one square inch – that is 2.54 × 2.54 centimetres.

A simple example: if there are 150 warp threads and 150 weft threads in one square inch, the result is a thread count of 300 TC. The distribution does not have to be even; in sateen, there are often more threads in one direction than in the other.

Important when comparing: some manufacturers state the density not per square inch, but in threads per centimetre or per square centimetre. These values cannot be compared directly with a TC figure. So only ever compare numbers that were measured in the same way.

The trick with twisted threads

A yarn can consist of a single thread (single-ply yarn) or of two or more thin threads twisted together (twisted or multi-ply yarn). Both are legitimate techniques. It only becomes a problem when every single strand is counted in the thread count.

A worked example

A fabric has 300 threads per square inch, each twisted from two thinner strands. Counted honestly, that is 300 TC. If you count each strand separately, the packaging suddenly says "600 TC" – even though there is not a single extra thread in the fabric. With three-ply yarns, 300 correspondingly becomes "900".

In the USA, the trade authority FTC made it clear in a statement back in 2005 that a thread count inflated by multiplying by the number of strands can mislead consumers. For you as a buyer, this means: a very high TC figure is first of all worth a question – namely, how it was counted.

Why 300 real threads is the more honest number

A 300 TC fabric made from fine single-ply yarns and a "600 TC" fabric made from 300 twisted yarns are two different products. Twisted yarns are thicker, so the fabric tends to be heavier and denser. Fine single-ply yarns produce a lighter, more supple fabric with a fluid drape. Which you prefer is a matter of taste. But the number on the label should not suggest that a fabric contains twice as much when that is not true.

That is why at Cottonbabe we state the thread count as it actually is in the fabric: our bed linen has a true 300 TC from single-ply threads – no twisted double threads that artificially increase the number.

What really counts besides the number

Thread count is just one feature among several. Whether bed linen feels high-quality and stays beautiful for a long time depends at least as much on these points:

1. The length of the cotton fibre

Not all cotton is the same. The longer the individual fibre (the so-called staple length), the finer and more evenly it can be spun into yarn. For our bed linen, we use extra-long-staple cotton, ELS for short, with a staple length of 34 to 38 millimetres.

2. The weave: sateen or percale

In sateen, the threads pass over several crossing threads before they are bound in. This creates the smooth, slightly lustrous surface that many people associate with luxury bed linen. Percale is woven in a plain weave – one thread over, one thread under. This produces a matt surface and a slightly cooler, "crisper" feel. Both weaves can be of high quality; the choice is a matter of personal preference. More on this: What is percale?

3. The finish

Many fabrics are treated with softeners or silicones after weaving so that they feel particularly soft in the shop. Our bed linen does without silicones and softeners – the feel you notice comes from the yarn and the fabric itself.

4. The workmanship

Seams, closures and details reveal a lot about the care taken in production. At Cottonbabe, the piping is a cord in yarn-dyed, chlorine-resistant sateen – a detail designed from the outset for frequent washing. In the shop, we deliver with concealed buttons. We make the hotel closure (envelope flap, no buttons) for hotels – and on request for you too: simply mention it in the order note when you order. You can read more in our guide to types of closure for bed linen.

5. Tested to OEKO-TEX Standard 100

An independent test seal such as OEKO-TEX® Standard 100 shows that a textile has been tested for harmful substances. Our bed linen is certified to OEKO-TEX® Standard 100.

300 TC for single items, 500 TC in the bundle

Our duvet covers, pillowcases and flat sheets have a true 300 TC. If you are looking for the next level, you will find it in the bed linen bundle in the Cottonbabe box: it has a true 500 TC – this quality is available exclusively with piping in Anthracite.

Our bed linen is made where the cotton grows: in India. And because a bed changes over the years, our reorder guarantee applies: the piping colours remain in our range for ten years from purchase, so you can reorder in a matching colour.

Checklist: how to check thread count claims

• Ask how it was counted: were single threads counted, or every strand of a twisted yarn?
• Check the unit: TC per square inch is not the same as threads per centimetre.
• Look at the fibre: is the cotton quality or staple length stated?
• Choose the weave: sateen for sheen and a fluid drape, percale for a matt, cool look.
• Question the finish: does the fabric only feel soft because of a coating?
• Look at the details: seams, closures, piping – and whether you can reorder later.

Conclusion

Thread count is a useful guide – but only if it is counted honestly. A figure of 600 or 800 TC says little as long as it is unclear whether twisted threads were counted more than once. It's better to look at the overall package of fibre length, weave, finish and workmanship.

You can find our bed linen with a true 300 TC here: First Class duvet cover, First Class pillowcase and First Class flat sheet. We deliver free of charge within Germany.

Source for the FTC statement: Home Textiles Today, "Thread count game slammed by FTC", 12.09.2005.