Two T-shirts can both say “100% cotton, 200 GSM” on the label and feel completely different — one soft and smooth, the other coarse and already pilling after five washes.
The difference isn’t in the spec people check. It’s in how the cotton was spun, and that detail rarely appears on a hang tag.
This guide covers what actually determines T-shirt quality, how to read a spec sheet, which fabrics suit which purposes, and how to make a shirt last. It’s part of our wider apparel and clothing section.
GSM: Useful, But Not What You Think
GSM means grams per square metre — fabric weight. It’s the most commonly quoted T-shirt spec and a useful shorthand for how substantial a shirt feels.
| GSM | Character | Typical use |
|---|---|---|
| 120–150 | Very light, can be semi-sheer | Summer tees, fashion-fit |
| 150–180 | Lightweight | Fashion tees, warm climates |
| 180–200 | Midweight — the everyday standard | General-purpose tees |
| 200–240 | Heavyweight, structured | Premium and streetwear tees |
| 240+ | Very heavy | Workwear, oversized styles |
What GSM doesn’t tell you is quality. A 240 GSM shirt made from coarse open-end cotton can feel rough, pill quickly, and shrink badly. A 160 GSM shirt made from combed ring-spun cotton will feel softer, last longer, and hold its shape — despite weighing 80 GSM less.
Weight tells you about substance. Yarn tells you about quality. They’re separate questions.
Yarn: The Specification That Actually Matters
Cotton goes through two independent processing decisions, and both affect the finished shirt.
Carded vs Combed
Carding mechanically untangles and aligns the fibres. It’s the baseline process.
Combing adds a further step that physically removes the shorter fibres, leaving only the long ones. Combed cotton is smoother, stronger, resists pilling better, and takes dye more evenly.
Combing uses roughly 15–25% more raw cotton to produce the same weight of yarn, which is why it costs more.
Ring-Spun vs Open-End
Ring spinning twists fibres continuously into a tightly aligned, fine yarn. The surface is smooth and the structure is strong.
Open-end (rotor) spinning blows fibres together — faster and cheaper, producing a coarser, fuzzier, weaker yarn.
The difference shows up in yarn count: ring-spun T-shirt yarn is typically 30s or 32s (fine), while open-end is often 18s or 20s (coarse).
The Two Decisions Are Separate
This is the part that trips people up. “Combed” and “ring-spun” describe different stages, and a supplier can do one without the other.
- Carded open-end — the budget baseline. Coarse, fuzzy, pills readily.
- Ring-spun — smoother and stronger. A clear step up.
- Combed ring-spun — both steps applied. The premium standard, and the phrase to look for on a spec sheet.
If a label says only “combed cotton,” it’s worth knowing whether it was also ring-spun. Combed open-end beats plain carded, but doesn’t match combed ring-spun.
Construction Details
These separate a shirt that holds up from one that doesn’t.
Side seams vs tubular. Tubular shirts are knitted as a continuous tube with no side seams — cheaper to make, but they twist after washing and lose shape. Side-seamed construction holds its form far better. This is the most common reason a shirt looks skewed after a few washes.
Shoulder-to-shoulder taping. A strip of fabric reinforcing the shoulder seam across the back. It stops the neckline stretching out over time and is a reliable quality marker.
Ribbed collar. A ribbed collar, ideally with a small percentage of elastane, springs back into shape. A plain jersey collar stretches out and stays that way.
Double-needle stitching on hems and sleeves — two parallel rows — is significantly more durable than single-needle. Easy to check by eye.
Pre-shrunk (compacted) fabric. Cotton shrinks on first wash. Pre-shrunk fabric limits this considerably. Untreated cotton knit can lose 5–10%.
Fabric Types
100% cotton — breathable, comfortable, takes dye and print well. Wrinkles, shrinks, and dries slowly. The default for good reason.
Cotton-polyester blends (usually 60/40 or 50/50) — more durable, less shrinkage, holds shape better, dries faster. Slightly less breathable. A sensible compromise for shirts that get washed constantly.
Tri-blends (cotton/polyester/rayon) — very soft with an excellent drape and a slightly heathered look. Popular for fashion tees. Less durable than pure cotton and more prone to showing wear.
100% polyester — quick-drying and durable, and the right choice for athletic wear where moisture management matters more than breathability. Retains odour more than cotton.
Pima and Supima cotton — extra-long staple cotton, noticeably softer and more durable. Supima is a trademarked designation for American-grown Pima. Premium pricing.
Organic cotton — grown without synthetic pesticides. Environmental rather than performance benefit; the feel depends on spinning and combing exactly as conventional cotton does.
Our fabric types and specs section covers fibre and construction in more depth.
Fit
Sizing isn’t standardised between brands, so measurements matter more than the letter on the label.
Measure a shirt you own that fits well and compare against the size chart. The key figures are chest width (measured flat across, then doubled), body length from the high point of the shoulder, and shoulder width seam to seam.
Fit types:
- Slim/fitted — close to the body; needs some stretch or it restricts movement
- Regular/classic — moderate ease, the traditional cut
- Relaxed — generous through the body
- Oversized — deliberately much larger, a style choice
Remember that fit changes after washing if the fabric wasn’t pre-shrunk.
Choosing a Blank for Printing or Embroidery
If you’re buying shirts to decorate, fabric choice affects the result more than most people expect.
For DTG printing, combed ring-spun cotton is strongly preferred. DTG sprays water-based ink onto the surface, and a smooth low-fuzz fabric gives sharp edges. On fuzzy carded cotton the ink wicks into stray fibres and detail blurs. Lighter combed tees (around 150 GSM) are a common DTG choice.
For screen printing, heavier ring-spun cotton (around 200 GSM) works well. The smoother surface lets ink film sit flat, producing crisper edges than carded cotton allows.
For embroidery, heavier fabric is better — it supports the stitching. A lightweight tee needs careful stabilising and still risks puckering.
For water-based and discharge inks, 100% cotton is essential. Discharge works by removing the garment’s dye, so it needs reactive-dyed cotton.
Our fabric printing section covers decoration methods in detail.
Making a T-Shirt Last
Wash cool. 30°C handles ordinary soiling. Hot water accelerates fading, shrinkage, and fibre breakdown.
Turn inside out, especially for printed shirts. This protects the print from abrasion and reduces surface fading.
Skip the tumble dryer where you can. Heat is the main driver of ongoing shrinkage and print cracking. Line drying meaningfully extends the life of a shirt.
Don’t overload the machine. Fabric needs room to move.
Fold rather than hang. Hanging stretches the shoulders of knitted fabric over time.
Wash with similar fabrics. Zips and rough fabrics abrade knits.
Common Problems
Shirt shrank after the first wash. Fabric wasn’t pre-shrunk, or it was washed too hot. Cotton knit can lose 5–10% on first wash.
Neckline stretched out. No shoulder taping, plain jersey collar rather than ribbed, or the shirt was repeatedly pulled over the head and hung by the shoulders while wet.
Shirt twists to one side. Tubular construction with no side seams. The knit relaxes in a spiral during washing. Not fixable — buy side-seamed shirts.
Pilling after a few washes. Short fibres working loose and tangling. Much more common with carded open-end cotton. Washing inside out on low agitation reduces it; a fabric shaver removes existing pills.
Print cracked or peeled. Usually undercured ink at the printing stage, accelerated by hot washing and tumble drying.
Colour faded fast. Hot washing, or a dye with poor fastness. Dark colours fade most visibly.
Fabric feels thin or see-through. Low GSM. Below about 150, lighter colours can be semi-sheer.
Where to Go From Here
- Apparel & Clothing — the full guide to reading garment construction and fit
- Fabric Types & Specs — GSM, jersey, interlock and yarn counts explained
- T-Shirt / Garment Printing — decoration methods and which fabrics suit them
- Fabric Printing — screen printing, DTG, sublimation and transfers
- Fabric Dyeing — if you’re dyeing shirts yourself
Related areas:
- Embroidery Machines — embroidering shirts, and why fabric weight matters
- Pants & Bottoms — the rest of the wardrobe
Frequently Asked Questions
What GSM is best for a T-shirt? Around 180–200 GSM for an everyday shirt. 150–180 for lightweight or warm-climate wear, 200–240 for a heavyweight premium feel. But GSM alone doesn’t determine quality — a 160 GSM combed ring-spun tee will outperform a 240 GSM carded open-end one.
What does combed ring-spun cotton actually mean? Two separate processes. Combing removes short fibres, leaving only long ones. Ring spinning twists fibres into a fine, tightly aligned yarn. Together they produce the smoothest, strongest, least pill-prone cotton fabric — and the phrase is the most reliable quality signal on a T-shirt spec.
Why does my T-shirt twist to one side after washing? Tubular construction — no side seams. The knit relaxes in a spiral during washing, pulling the shirt off-axis. It can’t be fixed once it happens. Side-seamed shirts don’t do this.
Is 100% cotton better than a blend? Depends on the use. Cotton is more breathable and comfortable but wrinkles, shrinks, and dries slowly. A cotton-poly blend holds shape better, shrinks less, and survives more washing. For athletic wear, polyester genuinely outperforms cotton. For a comfortable everyday shirt, cotton wins.
How do I stop T-shirts shrinking? Buy pre-shrunk (compacted) fabric, wash cool, and avoid the tumble dryer. Most shrinkage in cotton happens on the first wash and is driven by heat. Line drying essentially eliminates it.
Why do my T-shirts pill? Short fibres working loose under friction and tangling into balls. Carded open-end cotton pills much faster than combed ring-spun, because it contains more short fibres to begin with. Washing inside out and avoiding high heat helps; a fabric shaver removes existing pills safely.
What’s the best T-shirt fabric for printing? For DTG, combed ring-spun cotton — the smooth surface stops ink wicking into stray fibres. For screen printing, heavier ring-spun cotton around 200 GSM. For embroidery, heavier fabric supports the stitches better. Avoid fuzzy carded cotton for any detailed work.
How long should a T-shirt last? With reasonable care, a good combed ring-spun cotton tee should stay in decent shape for a few years of regular wear. Budget carded shirts often show pilling and neckline stretch within months. The yarn quality is the main variable, more than price alone.
