Fall programs are where wool and flannel enter the spec conversation, and both names arrive surrounded by confusion. The Super number on suiting is treated like a quality score when it is a fineness measurement, and “flannel” is used for any plaid shirt when it names a finish, not a pattern. We build woven garments at Kizen Lab in Bandung under FOB programs, and this is the fabric guide we give US brands speccing fall and winter.
The short answer: Super numbers measure fiber fineness in microns, and finer is softer but less durable, so Super 100s to 120s is the working range for garments worn weekly. Flannel is a finish, not a fiber or a pattern. Spec both by GSM per garment, and put the care path on the label from the start.
What do Super numbers actually mean?
Super numbers describe how fine the wool fiber is, measured against an old worsted-count system and understood today as average fiber diameter in microns: Super 100s sits at approximately 18.5 microns, Super 120s at approximately 17.5. Finer fiber means a softer, silkier, lighter cloth.
Finer is not better for daily wear. High-Super cloths crease more easily and wear less durably, which is why the working advice for garments meant to be worn weekly lands in the Super 100s to 120s range. Reserve the 150s for pieces that live carefully. Wool’s own wrinkle recovery, the fiber’s coil-like structure bending back instead of breaking, is one reason a wool garment survives a worn-for-a-day-then-hung life better than most fabrics, and why the spec conversation is about fineness rather than about avoiding wrinkles altogether.
Merino, lambswool, worsted: which wool is which?
Three names cover most spec conversations. Merino is a breed, and its fiber runs under 24.5 microns, graded fine, superfine, or ultrafine as the diameter drops. Lambswool is wool from the first shearing, staple 50 millimetres or under, valued for a soft, elastic hand. Worsted is the processing fork: combed so the fibers lie straight and parallel, which makes the cloth stronger, finer, and smoother, and is the classic suiting choice; woolen-spun yarns skip the combing and come out soft, bulky, and fuzzy. Spec by what the garment does: worsted for blazers and suiting, woolen-spun or lambswool for heavier, cosier cloth.
Is flannel a pattern or a fabric?
A fabric, and specifically a finish. The soft surface comes from brushing the woven cloth to raise a nap, or from loosely spun yarns; the fiber underneath can be wool, cotton, or a blend. The confusion is baked into the market: “flannel shirt” is often used for any plaid shirt, but the plaid is a pattern and the flannel is the fabric. A brand that specs “brushed cotton flannel, plaid” has said something precise; a brand that specs “flannel” alone has not. Flannelette, the napped-cotton member of the family, shows up in sourcing conversations and means the same finish on a lighter base.
Wool flannel tailors into blazers and winter suiting; brushed cotton flannel is the classic heavy shirt. For where those weights land in a range, our woven winter collection manufacturing overview shows the garment types built for the cold season. Both are specced by weight, by which face is brushed, and by the base fabric: wool flannel, cotton flannel, and flannelette each wear differently under the same name.
What gsm should wool and flannel garments be?
A weight ladder, in roughly these bands:
- Cotton flannel shirts: 135 to 200 GSM.
- Blazer and light suiting cloth: 180 to 230 GSM.
- Medium suiting and jacketing: 240 to 290 GSM.
- Winter suiting and heavy jacketing: 300 GSM and up.
Name the GSM in the tech pack and we confirm it on the actual rolls; weight decides drape, warmth, and how the garment photographs. The fabric GSM guide unpacks the number before you spec it. And when the calendar turns, the linen fabric guide for US clothing lines covers the warm-weather side of the rack.
How should wool and flannel garments be cared for?
Wool shrinks by felting: the fiber’s scales open with heat, moisture, and agitation, and latch onto each other into a mat that cannot be undone. That is why the care path we write, not improvise, matters: wool needs washing less than other fibers, tolerates machine or hand washing with a mild wool detergent, and never survives a hot tumble.
The other care risk is the clothes moth, whose larvae digest the keratin in wool. They target soiled fabric and dark, undisturbed storage, which is why the honest care instruction includes “clean before storing for the season.” None of this is hidden knowledge; it is the reason the labeling rules treat the care path as a spec item, and writing it into the tech pack is what makes the label honest instead of hopeful.
What do wool blends change?
Wool-polyester blends, commonly 80/20 or 90/10, cost less and resist wrinkles and abrasion better than pure wool. The trade is breathability, moisture management, and drape: the polyester share shows up in how the cloth wears. Spec the blend percentage; “wool blend” without a number is not a spec.
Wool and flannel: the quick answers
Is a higher Super number better wool?
It is finer, not better. Finer fibers feel softer and silkier but crease and wear more readily. Super 100s to 120s is the working range for weekly wear.
Is flannel a pattern or a fabric?
A fabric, and specifically a finish: the soft napped surface. Plaid is a pattern that can be printed on flannel or on anything else.
What GSM is a wool blazer?
Blazer cloth runs roughly 180 to 230 GSM, medium suiting 240 to 290, and heavy winter jacketing 300 and up. Cotton flannel shirts sit lighter, at roughly 135 to 200 GSM.
How do I stop wool garments shrinking?
Avoid heat, moisture, and agitation together: they felt the fibers into an irreversible mat. Wash with a mild wool detergent on a gentle cycle and skip the hot tumble.
How do I protect wool from moths?
Clean the garment before storing it; moth larvae target the keratin in wool and favor soiled fabric in dark, undisturbed places. Stored-clean is stored-safe.
Bring the fiber, the GSM, and the blend to the quote page at MOQ 500, FOB, and the fabric tests we run confirm the cloth before bulk. If the line mixes fibers, the rayon and viscose guide covers the other half of the rack.