Fabrics & Craftsmanship
What is flannel and when should you wear it?
- Written by
- The Roomten tailors
- Published
- 2026-09-05
- Last reviewed
- 2026-09-05
- Reading time
- 4 min
- flannel suits
- what is flannel
- winter suit fabric
- grey flannel
In short
Flannel is a soft, slightly brushed wool cloth, usually heavier than a worsted. It is warm, comfortable and quietly luxurious, and is best worn from autumn to spring in charcoal, navy or mid grey.
Flannel is one of the great British cloths. It is made by weaving woollen-spun yarn and then lightly brushing the surface to raise a soft nap. The result is a cloth that feels warmer, looks softer and photographs beautifully.
When to wear flannel
- Autumn to spring, when heavier cloth is welcome.
- Business and smart-casual settings where a sharper worsted would look cold.
- As a separate jacket with flannel or cavalry twill trousers.
Colours and weights
Charcoal flannel is the classic, followed by navy and mid grey. A 340–380g weight is ideal for a suit; heavier flannels are better as jackets or overcoats. Lighter flannel can be used for transitional suits but loses some of the characteristic softness.
Care
Flannel benefits from a clothes brush and occasional pressing. The nap can pick up lint, so keep a lint roller to hand. Because it is woollen-spun, it is slightly more prone to pilling than a worsted, but a well-made flannel suit will last for many winters.