Wool Flannel

Wool flannel is a soft woven wool whose surface has been lightly brushed (napped) to raise a fine fuzz of fibres. The nap partly hides the weave underneath and gives flannel its soft, matte, slightly blurry look and warm hand. It's usually woven as a plain weave or a twill, and comes in weights from light trouser flannel to heavy coating. Grey flannel trousers and skirts are the classic example, but it's also used for jackets, coats and fitted dresses.

"Flannel" alone can also mean cotton flannel (brushed cotton, as in shirts and pyjamas), which behaves differently. This page is about wool.

Worsted and woollen flannel

Wool fabrics are spun in two ways, and flannel comes in both:

• Worsted flannel is made from long, combed fibres spun into smooth yarn, then lightly brushed. It's finer, smoother, more durable, and holds a sharp crease, which makes it the choice for tailored trousers.
• Woollen flannel is made from shorter, carded fibres spun into a fuzzier yarn, then more heavily brushed and often slightly felted. It's softer, loftier, warmer and more casual, good for skirts, jackets and coats.

Choosing a weight

• Light (about 230-300 g/m², roughly 7-9 oz per square yard): trousers, skirts, fitted dresses.
• Medium (about 300-400 g/m²): jackets and structured skirts.
• Heavy (400 g/m² and up): coats.

Hold it up and drape it over your hand: a skirt flannel should fall smoothly. A fabric that stands stiffly away from your hand will make a stiff skirt.

Preparing it: pre-shrinking

Wool can shrink and relax when it meets steam and moisture, so pre-shrink it before cutting, even if the garment will be dry-cleaned. Otherwise the first heavy pressing during construction can shrink individual pieces unevenly. Options:

• Steam it thoroughly with an iron held just above the surface, working over the whole length, and let it dry flat.
• The damp towel method: roll the fabric in a damp (not wet) towel, leave it a few hours, then unroll and let it dry flat.
• Ask your dry cleaner to steam-shrink ("sponge") it.

Washable flannels can be machine-washed on a wool cycle before cutting if you intend to wash the garment, but expect some change in texture and test a swatch first.

Cutting with nap

Brushed flannel has a nap, so it can look slightly lighter or darker depending on which way the surface fibres point. Use a "with nap" layout, with all pattern pieces facing the same direction, so the colour doesn't vary from one piece to the next. Stroke the fabric: the smooth direction is "with the nap". Many tailors cut flannel with the nap running down.

Flannel sheds fibres when cut. Cut on a surface you can vacuum, and use sharp, heavy shears. Mark with tailor's tacks, chalk, or a tracing wheel with carbon tested on a scrap. Chalk brushes out of wool easily.

Sewing

• Needle: universal 80/12-90/14.
• Thread: all-purpose polyester, or silk thread for hand work and basting.
• Stitch length: 2.5-3 mm.
• Seam finishes: overlock or zigzag the allowances. For unlined jackets and skirts, a Hong Kong (bound) finish looks beautiful. Press seams open.
• Interfacing: a fusible designed for wool, or sew-in canvas for tailoring, at collars, facings, waistbands and hems. See Fusible Interfacing.
• Lining: a slippery lining (Bemberg/cupro, acetate or polyester) helps flannel skirts and trousers slide over tights and stops them clinging. See Lining Fabrics.

Pressing: where flannel shines (without shining)

Wool is the most rewarding fabric to press. With steam it can be shrunk, stretched and moulded into shape, which is the basis of tailoring. Flannel takes darts and seams beautifully: they press flat and stay flat. Three rules:

1. Always use a press cloth. Pressing wool directly with a hot iron creates permanent shine, especially on darker colours. Silk organza makes a good see-through press cloth. A damp cotton cloth adds steam.
2. Press, don't iron. Lower the iron, steam, lift. Don't slide it, which stretches the fabric.
3. Use a clapper. Press a seam with steam, then immediately press down on it with a wooden clapper until it cools. This sets a flat seam or sharp crease without shine.

Press over a tailor's ham for darts and curved seams, and slip strips of brown paper under seam allowances so their edges don't imprint through to the right side.

Why it's good for learning tailoring

Flannel forgives. The soft nap disguises small irregularities in stitching and pressing that would stand out on a smooth cotton, and the fabric shrinks and shapes willingly under steam, so set-in sleeves and shaped collars go in more smoothly. If you want to learn darts, sleeves, or a lined skirt, flannel is the fabric that makes it look easier than it is. See Tailoring vs. Dressmaking Traditions for the background to those techniques.

Care

Most wool flannel is dry-clean only, or hand-wash in cool water with a wool detergent and dry flat. Brush it regularly with a soft clothes brush, let garments rest between wears so the fibres recover, and store them clean, because moths prefer soiled wool.