Polypropylene base layers
The lightest common textile fibre. It absorbs almost no water, so it moves sweat away from skin quickly. It's a classic choice for cold-weather base layers.
How it’s made
- 1Polymerised from propylene and melt-spun into filaments.
- 2Knitted into close-fitting base layers.
What to look for
- Odour-control treatments, or blends with merino
Pros
- Very light
- Fast wicking
- Warm when damp
Cons
- Notorious for holding odour
- Low heat tolerance
Typical use
- Running:
- Winter base layers.
Sustainability
Fossil-based. Less common in recycled form.