Polyester is plastic. Here is the chain.
Not a metaphor and not an exaggeration. The same polymer as a drinks bottle, spun thin enough to knit.
Polyester is polyethylene terephthalate — PET. It is the same polymer family as a clear drinks bottle. That is not a rhetorical flourish; it is the same material, diverging late in the process.
The chain
- Crude oil or natural gas is refined into feedstock chemicals.
- Those become ethylene glycol and terephthalic acid.
- The two are polymerised into solid PET chips.
- The chips are melted and forced through a spinneret — a plate of very fine holes — producing continuous filaments.
- Filaments are drawn, textured, spun into yarn, and knitted into fabric.
A bottle takes those same chips and blow-moulds them instead. One branch of the process gives you packaging, the other gives you a t-shirt. The starting polymer is identical.
The rest of the family
Elastane — also sold as spandex or Lycra — is polyurethane. Nylon, or polyamide, is petroleum-derived. So is acrylic. Synthetics are now roughly two-thirds of global textile fibre production, and polyester alone accounts for more than half of everything made.
Why it won, honestly
It is worth being fair about this. Polyester is cheap, strong, holds dye brilliantly, resists creasing, and dries fast. Those are real advantages and they are why it took over. There is no conspiracy here — just economics doing what economics does.
The trade is that it does not absorb moisture, it sheds microfibres into the water supply with every wash, and it does not meaningfully biodegrade. For a raincoat, that trade is obviously worth making. For the layer against the thinnest skin on your body, all day, every day, it is at least worth making knowingly.
We are not asking you to throw anything out.
Only to notice that performance fabric and plastic are two names for the same object, and to decide for yourself where you want it.