Fibre encyclopedia
Polypropylene
Also called polypropylene · polipropilena · PP · polipropilen
The lightest fibre in common textile use. It floats, it takes in no water at all, and it is coloured before it becomes fibre.
Class
Synthetic
Comes from
From oil or gas
Where it comes from
Polypropylene is melt-spun from the polymer of the same name. It is less dense than water, which is unusual among textile fibres, and it does not accept the dyes used on other fibres, so pigment is mixed into the melt before spinning.
How it feels to wear
Air
Decided by the knit or weave, not by the fibre
Water
Water stays on the surface
Heat
Holds body heat
Stretch
A little stretch of its own
Wear
Holds up to hard rubbing
Polypropylene holds no water in the fibre at all, so moisture moves along the surface and out, which is why it is used as a base layer and as a lining under other cloth. It softens at a lower temperature than polyester or nylon, so a hot wash or a dryer will change its shape.
Care
- Wash cool.
- No dryer and no iron.
- Air dry; it takes minutes.
Because the colour is in the polymer rather than on the surface, polypropylene does not bleed dye and does not fade in the wash.
End of life
Recycling route
Mechanical recycling
As a plastic, polypropylene has a well established mechanical recycling route. As a textile it rarely reaches it, because textile collection is not sorted for it and the goods it is used in are usually bonded to something else.
In a blend
Polypropylene is often laminated to jute or paper for sacking, and bonded layers do not separate in sorting.
Skin notes
Mechanical
The filament is smooth. Polypropylene base layers are knitted to sit against the skin, so fit decides the friction rather than the fibre.
Chemical
Pigment sits inside the polymer rather than on the surface. Any antimicrobial finish added afterwards is not declared.
If your skin reacts to a garment, a dermatologist and patch testing are what can answer it. A label cannot, and neither can this page.
What the label cannot tell you
The label says polypropylene. It does not say what pigment is in the polymer, or whether an antimicrobial finish was applied on top.
Sources
- Regulation (EU) No 1007/2011 on textile fibre names and related labelling, Annex I. Checked 22 August 2026
- ISO 2076:2021, Textiles, man-made fibres, generic names. Checked 22 August 2026
Written from primary sources and in our own words. Where a figure could not be traced to a source anyone can open, it is not printed here.
Read the label you are holding
The scan surface reads one care label and names which questions it answers and which it leaves out. A passport says for one specific piece what a label cannot: the composition with its percentages, where the cloth came from, who worked on it, how to repair it and where it goes next.