Windproof
Windproof describes a fabric that blocks air passing through it. Unlike waterproofing, it has no widely published consumer standard, so the word is often used without a measurement behind it.
Air permeability can be measured, usually under ISO 9237, and expressed as airflow through a fabric. Very few consumer brands publish a figure, which means most windproof claims are descriptive rather than tested.
Why it matters
Moving air strips heat from the body far faster than still air at the same temperature. A wind-blocking layer over a fleece often feels warmer than a much thicker fleece alone, which is why a thin shell transforms comfort on a cold windy day.
How it is measured
ISO 9237 measures the rate of airflow through a fabric under a set pressure difference. A lower figure means less air passes and the fabric blocks wind more completely. Membranes and coatings are generally close to fully windproof; tightly woven fabrics without either are wind resistant rather than windproof.
Our own position
We describe VEAR products as windproof and we have no air permeability test to put behind that word. The fabric is coated, which in practice blocks wind effectively, but we have not measured it and we are not going to quote a figure we do not have. Everything we do and do not have data for is on our lab tests page.
Related terms
- Rain jacket vs windbreaker: the category built around this property
- Softshell: wind resistant rather than windproof
- Cycling to work in winter: where wind blocking matters most
- Glossary: all terms