Most founders can name a fabric “400gsm French terry, 100% cotton” and stop there.

That is a headline, not a spec.

Two fabrics can share the same headline and feel like different products in the hand, shrink differently in the wash, and cost you different amounts per unit.

The gap is literacy.

A fabric spec sheet packs a dozen decisions into a small table, and each field tells you something about how the garment will look, feel, last, and price.

Read it well, and you stop being at the mercy of whatever a supplier sends.

You start comparing like a buyer.

This is the definitive read on that skill for a streetwear brand.

We’ll go field by field, then deep on the four that decide everything: composition, weight, construction, and finish.

Cover the one thing no number can tell you (hand) and finish with the exact spec a factory needs to quote you accurately. No filler.

Every section is something you can use on the next quote you request.

We build to spec every day on our own floor in Sialkot, so the examples here are the real fields we quote and test against, not a textbook.

The Four-Layer Read:

Every fabric spec answers four questions in order. Read it top to bottom, and you’ve understood the fabric before you ever touch it.

This is the frame we’ll use for the whole guide.

01

Composition:
What it’s made of: the fibers and their ratio.
Decides: feel, stretch, durability, care, cost floor.

01

Weight:
How much of it there is: GSM, plus the yarn and knit behind it.
Decides: heft, structure, warmth, perceived quality, price.

01

Finish:
What’s been done to it after knitting: washing, brushing, dyeing, and softening.
Decides: surface, softness, color behavior, and shrinkage.

01

Hand:
How it actually feels, the one layer no number can give you.
Decides whether the first three add up to what you wanted.

01

The fields on a fabric spec sheet:

A spec sheet looks intimidating because it’s dense, not because it’s complex.

There are only about a dozen fields that matter, and each one answers a plain question.

Learn what each row is telling you, and the whole sheet opens up.

Here’s the thing to hold onto: a spec sheet is a description of a physical thing, written in shorthand.

Every field exists because two people, you and the factory, need to agree on exactly what will be made before anything is cut.

Vague fields lead to a garment that’s technically “correct” and not what you pictured.

Precise fields are the difference between a fabric you can reorder identically in a year and a lucky one-off.

Below is the anatomy of a typical knit spec sheet for streetwear.

Read the middle column; that’s what each field actually decides for you.

Field What it tells you Watch for
Fabric name The construction is in one phrase (e.g., “French terry,” “single jersey,” “loopback fleece”). A name is a category, not a promise. Everything below refines it.
Composition The fibers and their ratio: 100% cotton, 80/20 cotton/poly, and 95/5 cotton/elastane. Ratios move cost and feel. “Cotton-rich” is not a spec.
Weight (GSM) Grams per square meter, the single best proxy for heft and perceived quality. Always ask for a tolerance (e.g., ±5%). GSM with no tolerance is a wish.
Yarn count Yarn fineness (e.g., 20s, 30s) and whether it’s ring-spun or open-end, combed or carded, single or ply. This is where “cheap 300gsm” and “premium 300gsm” diverge.
Construction/gauge How the yarn is knitted: jersey, terry, interlock, and rib; and the machine gauge. Same fiber + same GSM, different construction = different garment.
Width Cuttable width (open or tubular), in cm/inches, drives fabric consumption and cost. Low width can quietly raise your per-unit fabric cost.
Finish Post-knit treatments: bio/enzyme wash, brushing, peaching, softener, and anti-pill. Finished changing hands and shrinkage more than founders expect.
Dye method Yarn-dyed, piece-dyed (reactive/pigment), or garment-dyed. Garment dye = character + more variance. Plan for it.
Shrinkage Expected dimensional change after wash, as a tolerance (e.g., ±5%). No shrinkage figure = no way to grade your pattern correctly.
Colorfastness How well color holds to washing, rubbing (crocking), and light, graded 1–5. Dark, heavily dyed streetwear is where this bites. Test it.
Pilling/abrasion Resistance to bobbling and wear, graded on a standard test. Cheap yarn pills. This field is your early warning.
Stretch & recovery Only if elastane is present, how far it gives, and whether it bounces back. Stretch without recovery = bagging at the elbows and knees.

You don’t need every field on every project.

But you should never accept a fabric where the fields that matter for that product are blank.

A summer tee lives or dies on GSM and yarn.

A heavyweight hoodie lives or dies by GSM, construction, and shrinkage.

A stretch piece is all about recovery.

The three fields founders skip and shouldn’t:

Yarn count. This is the most-ignored field and one of the most important.

Two 180gsm jerseys can feel completely different because one uses a fine, combed, ring-spun yarn and the other a coarse, carded, open-end yarn.

GSM tells you how heavy; yarn tells you how nice.

For the full breakdown of what a fiber and yarn call-out means, see our tech pack essentials guide.

Tolerances. A spec without tolerances isn’t a spec; it’s an aspiration. GSM ±5%, shrinkage ±5%, colorfastness grade 4 minimum.

Tolerances are what you actually test bulk against.

Without them, you have no basis to reject a bad delivery because nothing was ever agreed upon.

We cover why weight tolerance matters so much in the GSM-explained guide.

Construction. “French terry” and “loopback fleece” and “single jersey” aren’t finishes on the same base; they’re different knits with different behavior, drape, and cost.

Getting fluent in construction is half the battle; our knit vs woven primer is the fastest way in.

From our floor:

The single most common reason a bulk delivery disappoints is a spec that names the fabric but never names the yarn, the tolerance, or the finish.

The factory made something reasonable, just not your something.

Fill the fields, and that gap closes.

02

Composition, GSM, construction & finish:

Four fields do most of the work.

If you only ever get fluent in these, you can evaluate 90% of streetwear fabrics with confidence.

Here’s what each one really controls and the traps inside each.

Composition: what it’s made of

Composition is the fiber content and ratio.

It sets the baseline for feel, durability, stretch, care, and cost. In streetwear, you’ll mostly see a handful:

  • 100% cotton: soft, breathable, takes print and dye beautifully, the streetwear default. Shrinks and creases more; costs vary hugely by yarn quality.
  • Cotton/polyester (e.g., 80/20, 50/50): poly adds durability, reduces shrinkage and price, and helps fleece keep its shape. The trade-off is a slightly less premium, less breathable hand.
  • Cotton/elastane (e.g., 95/5): a touch of elastane for stretch and recovery, common in fitted tees and ribbing.
  • Poly/cotton/elastane tri-blends: soft, drapey, marled looks; popular for elevated basics.
  • Recycled / organic variants, recycled polyester (rPET), or organic cotton carry a cost premium and a claim you must be able to document.

The trap: ratios are money.

Shifting from 100% cotton to 65/35 cotton/poly changes cost, shrinkage, and hand all three.

“Cotton-rich” or “cotton blend” on a spec is a red flag; make the supplier state the exact split.

Weight (GSM): How much of it?

GSM (grams per square meter) is the industry’s shorthand for heft.

Higher GSM generally means a denser, warmer, more substantial, more “premium-feeling” fabric, and more fabric cost per garment.

It’s the number buyers reach for first because it correlates so strongly with perceived quality.

Product Typical GSM band Reads as
Lightweight tee 140-160 gsm Summer, drapey, fast-fashion price
Midweight tee 180-220 gsm Everyday quality holds shape
Heavyweight/boxy tee 230-280 gsm Premium, structured, “vintage” feel
French terry crew/hoodie 280-380 gsm Year-round, softer inside
Heavyweight fleece hoodie 400-500+ gsm Luxury heft, statement weight

Two traps live here.

First, GSM without a tolerance is meaningless; bulk will drift, so agree on ±5% (or tighter) and test it.

Second, GSM isn’t the whole quality story. A 300gsm fabric in coarse open-end yarn can feel cheaper than a well-made 240gsm in combed ring-spun.

Weight and yarn together tell the truth.

The way premium feel is built and how to point a customer at it connects to our guide on reading quality cues in a garment.

Construction: How is it knitted?

Construction is the structure the yarn is knitted into.

It’s why two fabrics of identical fabric and weight can behave completely differently.

The ones you’ll meet in streetwear:

Single jersey:

The classic tee knit. Light, smooth face, curls at the edges. Different weights cover most tees.

French terry:

Loops on the inside, flat face outside. The go-to for crews and lighter hoodies is soft but not fuzzy.

Fleece (brushed-back):

French terry with the loops brushed into a soft nap. Warmer, plusher, heavier is the hoodie standard.

Loopback / loopwheel:

Premium terry knit slowly on wide machines for a denser, more even, more collectible fabric.

Interlock:

Smooth on both faces, more stable and structured than jersey. Good for elevated basics and layers.

Rib (1×1, 2×2);

Stretchy, textured. Used for cuffs, hems, and collars, and as a body fabric for fitted pieces.

The trap: founders treat construction as a game to copy off a competitor.

But construction interacts with weight and finish.

A brushed 350 gsm feels heavier and warmer than an unbrushed 350 gsm terry, even at the same number.

Always read construction and weight together.

Finish: What’s been done to it?

Finishing is everything applied after the fabric is knitted.

It’s the least understood field and one of the most powerful, because it changes the two things customers notice first:

How the fabric feels and how the color behaves.

  • Bio/enzyme wash removes surface fuzz, softens the hand, and reduces pilling. Comes in quality cotton.
  • Brushing raises a soft nap (turns terry into fleece). Adds warmth and plushness.
  • Polishing/emery: a fine sanding for a peach-skin surface.
  • Silicone softener for a slick, soft hand. Pleasant, but can affect print adhesion. Flag it if you’re printing.
  • Anti-pill finish (or a better yarn) to resist bobbling on fleece.
  • Garment dyeing the finished garment, not the fabric, for a lived-in, tonal look. Beautiful, but expect more shrinkage and shade variance.

The trap: finishing quietly moves shrinkage and hand, so a finish change is a spec change.

If a supplier “improves” the softness, ask what they changed and retest shrinkage.

Never assume the sample you loved and the bulk you approved share a finish unless it’s written down.

Rule of thumb:

Composition sets the floor, weight sets the heft, construction sets the behavior, and finish sets the feel.

Change any one, and you’ve changed the fabric even if the headline name stays the same.

03

What does “hand” mean, and how do you judge it?

Hand, or “handfeel,” is the one thing a spec sheet can’t give you.

It’s the tactile character of the fabric, and it’s where a spec that looks identical on paper turns into two products that feel worlds apart.

Every field so far has been a number or a name.

Hand is neither. It’s the sum of all of them, felt through your fingers, and it’s the layer that decides whether the fabric you specified is actually the fabric you wanted.

You can’t read or hand off a sheet, but you can judge it systematically. Professionals assess a handful of dimensions:

Softness:

Harsh vs. soft against skin. Driven by yarn quality and finish, not just fiber.

Weight-in-hand:

Does it feel as substantial as the GSM promised? Density you can feel.

Surface:

Smooth, dry, slick, peached, brushed. How the face reads to the fingertip.

Drape:

Does it fall and flow or stand stiff? Governs how the finished garment hangs.

Recovery:

Stretch it gently does it spring back or stay deformed? Predicts bagging.

Compression:

Squeeze it: dense and resilient, or thin and empty? Tells you the yarn’s honesty.

How to actually judge a hand?

Do these four things, in this order, every time:

  1. Feel a physical swatch, never a photo or a screen. The hand is tactile by definition. A picture tells you color and maybe surface; it tells you nothing about softness, drape, or recovery. This is the non-negotiable rule of fabric buying.
  2. Feel it at the real bulk weight. A hand-loom sample or a light “reference” swatch will feel different from production fabric. Ask for a swatch at the exact GSM, and finish; you’ll run, not an approximation.
  3. Compare against a benchmark. Hand is relative. Hold your candidate next to a garment whose feel you already trust, a competitor piece, or a past bulk you liked. Differences jump out that you’d miss in isolation.
  4. Wash it before you sign. Finish and softener can wash out. A fabric that feels lovely in the swatch and rough after one wash has failed. Test the after-wash hand, not just the showroom hand.
The one rule:

Never approve a fabric from a photo, and never from a swatch that isn’t at your real bulk weight and finish. Hand is the layer that turns a good spec into a good garment, and the only way to check it is with your hands on the real thing, ideally after a wash.

This is also why we send a physical sample at true bulk weight before any order is confirmed.

A spec gets you 90% of the way; hand is the last 10%, and it’s the 10% your customer feels first.

04

Matching spec to product and price point:

A spec isn’t good or bad in the abstract; it’s right or wrong for a specific product at a specific price.

Over-spec a basic, and you kill your margin.

Under-spec a hero piece, and you kill your reputation.

Here’s how to match the two.

Every field on a spec sheet has a cost.

Finer yarn costs more. Higher GSM costs more.

Combed beats carded, ring-spun beats open-end, loopback beats standard terry, and garment dye beats piece dye, and each step up adds cents or dollars per unit.

The skill isn’t maxing every field.

It’s spending your fabric budget where the customer will feel it and saving it where they won’t.

Start from the product’s job:

Ask what the piece has to do, then spec to that:

  • Basic volume / blank-tier tee: the job is acceptable quality at a defensible price. Midweight jersey, decent-but-not-premium yarn, reliable finish. Don’t pay for loopback here.
  • Signature Hero Hoodie: The job is to feel unmistakably premium.

    Heavyweight fleece, combed ring-spun yarn, loopback construction, and considered finish. This is where you spend.

  • A fitted/technical piece, the job is fit and recovered. Composition with elastane, tested recovery, and stable construction. Weight matters less than stretch behavior.
  • Fashion/seasonal drop: the job is a look. Garment dye, unusual construction, and distinctive hand: accept more variance for more character.

The margin logic, plainly:

Fabric is usually the largest single input in a garment’s cost.

So a spec decision is a margin decision. Two moves protect you:

Match the spec to the price you can charge. A 500 gsm loopback hoodie in premium combed yarn cannot be a $40 retail product; the fabric alone won’t allow it.

If the market caps your price, the spec has to fit under that ceiling.

If your brand can command a premium, underspecing the fabric leaves both quality and money on the table.

Spend on what’s felt; save on what’s hidden. Customers feel weight, softness, and surface immediately.

They rarely notice a mid-tier width or a standard (vs. premium) anti-pill finish.

Direct budget to the fields that touch the customer’s hand, and the perceived-quality gap between you and a pricier competitor narrows fast.

If the product is Spend on Safe to save on
Volume basic Consistent GSM, reliable colorfastness Loopback, garment dye, premium finish
Hero hoodie GSM, combed ring-spun yarn, construction, hand Exotic composition: keep it clean cotton/blend.
Fitted piece Elastane percentage, recovery, fit consistency Ultra-high GSM (adds weight, not fit)
Seasonal drop Distinctive finish/dye, character Long-term durability specs (short life)

Fabric is the biggest lever on both perceived quality and unit cost, which is why this is a pricing decision as much as a product one.

If you’re setting or revisiting price, the fabric-spec choice feeds directly into it and is worth reading alongside how quality cues justify a premium.

Protect the margin:

The right spec is the cheapest one that still does the product’s job at the price you can charge.

Not the most impressive spec, not the cheapest, but the right-fit one

That’s the discipline that keeps a growing brand profitable.

05

Specifying fabric so factories quote accurately:

A vague brief gets you a padded, hedged, or simply wrong quote and a first sample that isn’t what you meant.

A complete spec gets you an accurate quote and a right-first-time sample.

Here’s the exact spec a factory needs from you.

When a factory receives a fuzzy request, “Quote me a heavyweight cotton hoodie,” they do one of two things:

They pad the price to cover the uncertainty, or they guess at a spec and quote something you didn’t ask for.

Either way you lose: an inflated number or a sample round wasted on the wrong fabric.

The fix is to hand over a complete fabric spec up front. It doesn’t need to be fancy.

It needs to be specific.

When every field a factory prices against is filled in, the quote comes back tight, and the first sample lands close.

The Quote-Ready Spec:

This is the checklist we wish every inquiry arrived with.

Fill these in, and a factory can quote you accurately, without padding and without guessing:

01
Composition, exact ratio:
“80/20 cotton/polyester,” not “cotton blend.” The split changes the price.
02
GSM + tolerance:
e.g., “350 gsm ±5%.” The tolerance is what bulk gets tested against.
03
Construction:
French terry, loopback fleece, single jersey, interlock name the knit.
04
Yarn spec:
Count (e.g., 30s), ring-spun vs. open-end, combed vs. carded, single vs. ply.
05
Finish:
Bio-wash, brushed, peached, softener, anti-pill: list what you want applied.
06
Dye method & color standard:
Reactive/pigment/garment dye, plus a Pantone or physical color reference.
07
Test standards to hit:
Shrinkage tolerance, colorfastness grade, and pilling grade you’ll accept.
08
Quantity & sizing curve:
Target units per color/style; it changes fabric pricing and feasibility.
09
A reference swatch, if you have one:
A physical benchmark removes ambiguity faster than any description.

Nine lines. That’s the whole thing.

A factory reading that can price it in one pass, because there’s nothing left to assume.

The reason precise specs unlock accurate numbers and how a quote is actually built up on the factory side is covered in our guide to how factories build a quote.

What does a vague spec cost you?

  • Padded pricing uncertainty gets priced in as risk. You pay for the factory’s caution.
  • Wasted sample rounds are a guess at your spec, which means a sample that’s off, and every extra round costs time and money.
  • Apples-to-oranges quotes: If you send a fuzzy brief to three factories, they’ll each spec it differently, and you can’t compare the numbers at all.
  • No basis to reject bulk: nothing tested against, nothing to hold the factory to.

Send the same complete spec to every factory, and their quotes finally become comparable, using the same fabric, so the difference is genuinely price and capability, not spec drift.

Bottom line:

An accurate quote is downstream of a complete spec.

Fill the nine lines above, and you turn a guessing game into a comparison, which is exactly the position a founder wants to negotiate from.

From the manual

This is one chapter of The Complete Streetwear Manufacturing Guide

These chapters cover taking a streetwear brand from idea to shipped units, costing, sourcing, tech packs, QC, freight, and launch. All written from the Sialkot factory floor.

Open The Full Guide

Fabric spec questions, answered

A fabric spec sheet is a short technical description of a fabric, written in shorthand so a brand and a factory can agree exactly what will be made before anything is cut.

It lists the fields that define the fabric composition, weight (GSM), yarn, construction, finish, dye method, and the test standards it should meet, like shrinkage and colorfastness.

Think of it as a contract for how the garment will feel and hold up.

The more complete it is, the less room there is for the bulk delivery to surprise you.

GSM stands for grams per square meter, the weight of the fabric.

Higher GSM generally means denser, warmer, and more substantial, which is why buyers use it as a quick proxy for quality.

But higher isn’t automatically better.

A high-GSM fabric in coarse, cheap yarn can feel worse than a lighter fabric in fine, combed yarn, and it costs more and adds weight you might not want.

Read GSM together with yarn and construction, and always match it to the product’s job and price point.

Because GSM only measures weight.

The feel comes from the fields around it: the yarn fine vs coarse, combed vs carded, and ring-spun vs open-end; the construction (jersey vs terry vs loopback); and the finish (washed, brushed, softened).

Two 300gsm fabrics can share that number and differ in every other field, so they feel like different products.

This is exactly why you should never buy on GSM alone and never approve a fabric without feeling a physical swatch at the real bulk weight.

Hand is the tactile character of a fabric: how soft, dense, smooth, drapey, and resilient it feels in your fingers.

It’s the sum of composition, weight, construction, and finish, and it’s the one thing a spec sheet can’t put into numbers.

You judge it by feeling a physical swatch at the true bulk weight and finish, comparing it to a benchmark you trust, and ideally washing it first since some softness comes from finishes that can wash out.

No. A photo can show color and, roughly, surface, but it tells you nothing about softness, weight in hand, drape, or recovery, which are the things a customer feels first.

Approving from an image is the most common way brands end up with a bulk of fabric they didn’t expect.

Always approve from a physical swatch at your real bulk weight and finish.

It’s the single most reliable habit in fabric buying.

Give the complete spec: exact composition ratio; GSM with a tolerance; construction; yarn spec; finish; dye method and color reference; the test standards you’ll accept (shrinkage, colorfastness, and pilling); your target quantity; and a physical reference swatch if you have one.

A complete spec gets you a tight quote and a right-first-time sample.

A vague one gets you padded pricing, wasted sample rounds, and quotes you can’t compare across factories.

They start from the same family.

French terry has loops on the inside face and a flat outer face, soft but not fuzzy.

Fleece is French terry with those inside loops brushed into a soft, warm nap.

So fleece is warmer, plusher, and usually reads heavier at the same GSM.

French terry suits lighter hoodies and crews; brushed fleece is the classic for a warm, substantial hoodie.

Bulk production always drifts a little, and tolerances are what you agree to accept.

GSM ±5%, a minimum colorfastness grade, and a shrinkage range these give you a concrete standard to test the delivery against.

Without tolerances, nothing was ever really agreed upon, so you have no basis to reject a bad batch.

A spec without tolerances isn’t a spec; it’s a hope.

On the floor · Sialkot

Written by

Faizan Ahmad

Chief Apparel Technologist & Head of Manufacturing, Gibben Clothing · Sialkot, Pakistan

Faizan leads production at Gibben Clothing, a cut-and-sew streetwear manufacturer in Sialkot, with 8+ years turning raw yarn into retail-ready hoodies, tees, bottoms, jackets, tracksuits, and headwear. He doesn’t just write about clothing; he works the floor, so every guide here is grounded in real fabric behavior, QC standards, and production data from live runs.