Materials Up Close & Personal: TOWELS
07 May 2020
Towels are some of our most intimate textiles, touching places that other textiles just don’t reach. This distinctive, plush and mildly abrasive fabric is one that most of us have experienced on a daily basis since childhood. But how well do we really know it?
As you’ll be aware if you’ve ever been caught short and had to dry yourself on your pants or a bed sheet, towels are a wondrous and thirsty piece of technology, perfectly designed to wick all moisture from our skin. But it’s taken decades of work by manufacturers and textile technologists to arrive at this pinnacle of achievements: today’s bath towel.
Whereas flat cloth is normally woven with two threads (warp and weft) that sit at right angles to each other, ‘pile’ fabrics like carpets and towels involve a third thread. This extra thread is left loose, whilst the other two are kept taut: when the loose thread is pulled through the dense network of tight threads, it forms loops on either side. The resulting towel material is called terry cloth, a name that is said to have come from the French verb tirer, meaning ‘to pull’.
Different towel fabrics under a clip-on phone magnifier, taken by Zoe Laughlin
The tufted, looped fabric that we now take for granted has only been around in western Europe since about 1840. The method for making towels on hand looms was invented in Turkey, apparently as the accidental result of defective weaving. Manchester-based textile tycoon Henry Christy brought these fabrics to the UK in the mid 1800s, where he promptly copied and industrialised the manufacturing technique. Christy are still producing towels to this day, and are the main supplier to the Wimbledon tennis championships, where most are thrown into the crowd as sweaty mementos for eager fans.
The secret to a towel’s superb absorbency lies in the fibres used, the characteristics of the yarn, and its woven structure. Most towels are made from cotton, although silk, synthetic and even nettle and wood fibres have all been tried and tested. The reason we often fall back on cotton is that, once processed, it is hydrophilic. The long chains of cellulose that make up cotton fibres have lots of negatively charged parts to their molecular structure, and these attract the positively charged hydrogen atoms in water molecules. Cotton fibres are also hollow, so there’s plenty of space to store the water until it evaporates. For this reason, cotton is able to absorb up to 27 times its own weight in water, but also stays damp and clammy for a long time.
Towel fibres close up, image by rvoegtli
This already absorbent fibre is made even more porous by weaving it into a very open yarn structure, so there is plenty of space in the middle of the thread itself. These thin, air-filled tubes of cotton exert capillary pressure on any water they come into contact with: water molecules like to stick to the sides of these tiny, hydrophilic cotton straws more than they like to stick to each other, so water is sucked up into the towel.
Moisture-wicking yarn is then woven into the distinctive series of loops that further increase a towel’s ability to absorb by increasing the surface area of cotton in contact with your skin. The loops double as an exfoliant, mildly abrading our skin when we dry ourselves, removing dirt, oils and dead skin cells. Its surface texture is also what makes a towel so warm: air that is trapped in the loops acts as an insulator, which is why it’s such a relief to wrap yourself in this fabric after a cold swim.
We now know what makes for an ideal absorbent cloth, so how come we still occasionally encounter that obstinate towel that just won’t dry us off properly? Aside from how well it performs its primary function of wicking water, towel manufacturers are also concerned about what a towel looks like, how soft and pleasant it feels on the skin, and how easy it is to clean, for example. For that reason they will often include silk fibres to improve the lustre of a towel or synthetic fibres that dry more quickly, even though they are not as absorbent. Towel makers will also sometimes cut and crop the loops on one side of a towel to make ‘velour terry’, which has a lower surface area for absorbing water, but feels more velvety and shows a pattern really well.
Terry cloth isn’t just familiar to us from our beach, bath and tea towels: you will no doubt also have encountered wearable towel at some point in your lives. Maybe in the form of the timeless and luxurious terrycloth bathrobe, transient Juicy Couture joggers (if you were a teenager in the nineties) or that excellent baby blue towel rompersuit sported by Sean Connery in Goldfinger. Before the invention of disposable sanitary pads in the 1920s, sanitary towels would have been made of actual towel. This may sound uncomfortable, but was a vast improvement on some earlier menstrual technologies, including the ‘fine wood shavings and pulverized moss’ proposed in Germany in the 1890s. If wearing a towel out of the house sounds a bit strange, you may have experienced terry cloth’s more sophisticated younger sister, French terry. This lighter and stretchier version of the towel has only one side covered in pile. Check out your cosiest sports hoodie and you might find a layer of fuzzy tufts all over the inside: perfect for absorbing your post-workout glow.
Perhaps because of its familiarity and distinctive feel, towel also makes an appearance as an archetypal textured material in studies exploring people’s responses to tactile stimulation. For example, it is used in work with people with autism to identify sensory modulation dysfunction (when a person reacts in a seemingly disproportionate way to a non-noxious sensation like towel on the skin). Terry cloth is also used in desensitization therapies as a way of helping people to adapt to and manage chronic pain after amputation, trauma or surgery.
About our new blog series 'Materials: Up Close & Personal'
We are excited to announce a new series of Materials Library profiles. Over the next few months our Materials Librarian Sarah Wilkes will be paying homage to those silent and humble materials that we surround ourselves with daily, but that often we don’t even notice. Every week or so, she will be exploring the expansive inner lives and backstories of the surfaces, substances and stuff around us, and sharing it with our community through our blog and social media #MaterialsLibraryUpCloseAndPersonal.
We would love you to join in too! Send us a picture of one of your favourite household substances with a few words about what you’ve noticed after spending some time getting to know your material cohabitants. A collection of these little gems will go up on our website soon.