We get asked all the time: why go to the trouble of weaving a towel from recycled plastic bottles when cotton has worked beautifully for several thousand years? The short answer is that cotton is a wonderful material for a bathroom and a terrible material for a beach bag. The long answer involves surface area, hydrophilic chemistry and a bit of history.

Cotton: lovely in the laundry, miserable in a backpack

A standard beach towel measuring roughly 160 by 90 centimetres and weighing 500 to 700 grams dry can take on well over a litre of water in a single swim. It holds that water tightly — cellulose fibres have hydroxyl groups that bond to water molecules — which is why your cotton towel comes home from the beach heavy, damp and smelling of itself. It will dry, slowly, if you spread it in the sun. In a packed suitcase, it will not dry at all.

Cotton also loves sand. The looped pile that gives it that soft touch traps grains at every pass, and in our experience no amount of shaking out will remove them. We’ve measured. On a Mykonos beach, in a wind-tunnel experiment at home (don’t ask), a cotton towel retained 40 to 60 grams of sand after a hard shake. A microfibre towel retained 2 to 3.

Microfibre: a different mechanical story

Microfibre is a very thin, non-circular synthetic fibre — ours are drawn from recycled PET plastic bottles. Each individual thread is roughly one hundredth the width of a human hair. The result is extraordinary surface area: a square metre of woven microfibre may expose fifteen to twenty square metres of filament to the water it touches.

That surface area is why microfibre absorbs so quickly — up to four times its own weight — and why it releases water so quickly as well. The water sits between the fibres rather than bonding chemically to them, so a brisk wring followed by a hang in the sun means a towel dry in fifteen to twenty-five minutes.

The numbers that matter when you travel

Here is the comparison in brutal practical terms, from our own in-house tests:

  • Weight (dry): cotton ~600 g; our microfibre ~320 g
  • Packed volume: cotton rolls to the size of a loaf of bread; microfibre to the size of a paperback
  • Time to dry hung in sun at 25 °C: cotton 120–180 min; microfibre 20–25 min
  • Sand retained after shake: cotton 40–60 g; microfibre 2–3 g
  • Absorption: cotton 2× dry weight; microfibre 4× dry weight

What microfibre is not good at

We should be honest. Microfibre does not have the plush, bath-mat feeling of a thick terry cotton towel. It is a different sensation — more a cool, smooth cloth than a warm hug. For your bathroom after a long shower, cotton still wins. For the beach, the pool, the campsite and the hostel? It isn’t close.

There is also one caveat: synthetic microfibre, in general, can shed microplastics during washing. We address that in two ways. First, by making our fibre from already-polluted PET feedstock (ocean-bound and post-consumer bottles) — we are not creating new plastic for the planet. Second, by weaving at a density that minimises shedding, and by recommending a Guppyfriend wash bag for the first few washes, when shedding is highest.

The verdict

Microfibre is the right tool for the right job. Our towels are built for travellers, swimmers, parents of small sandy children, people who ride bicycles to swimming holes. They are not built to be your bath towel. Keep the cotton for home; the recycled microfibre for everywhere else.