Spec guide
Read the spec before the price.
Two blank tees can carry the same 180 GSM number and feel nothing alike. The number that gets printed on the listing is only one of nine fields, and the rest is where the money and the fit actually live. Here is what each field means, which ones change the price, and the questions worth asking before you commit to a style number.
This page is a buying guide, not a sales page. Every figure on it is a published industry reference, and the section at the end says exactly which fields our own spec sheets do and do not cover.
Field one to nine
The nine fields on a blank.
Most distributors list the same nine. Only the first one gets talked about.
Field
What it is
Why it matters
Weight (oz/yd² or GSM)
What it is
Mass per unit area of the finished fabric.
Why it matters
Drives fabric cost almost linearly. 1 oz/yd² = 33.9 g/m².
Yarn count (Ne)
What it is
How fine the yarn is — 30s is the standard tee count.
Why it matters
180 GSM in 30s is denser and smoother than 180 GSM in 20s.
Ring-spun or open-end
What it is
How the fibres were twisted into yarn.
Why it matters
Ring-spun is softer, stronger and less hairy — and dearer to make.
Combed or carded
What it is
Whether short fibres were combed out before spinning.
Why it matters
Combing takes out roughly 12–20% of the fibre; less pilling, smoother hand.
Tubular or side-seamed
What it is
Body knitted as a tube, or cut as panels and joined at the sides.
Why it matters
Side seams hold the garment straight in the wash and give a printer a registration edge.
Hem and sleeve finish
What it is
Single-needle stitch or coverstitch.
Why it matters
Cheap hems are the first thing to ripple after a few washes.
Pre-shrunk / compacted
What it is
Whether the fabric was mechanically shrunk before cutting.
Why it matters
Untreated cotton jersey shrinks 5.0–7.5%; compacting brings it to the ±3% most brands write.
Neck construction
What it is
Rib weight, taping, seam type.
Why it matters
Shoulder-to-shoulder tape is the cheapest visible sign of a serious garment.
Label type
What it is
Tearaway or sewn-in.
Why it matters
A tearaway saves you a relabelling operation; a sewn-in one does not.
Weight
Ask which weight it is.
Weight is measured on finished, conditioned fabric — the standard is ASTM D3776. Greige weight (straight off the knitting machine, before dyeing and finishing) and finished weight differ by 5–15%. A spec that does not say “finished” has not specified anything.
US listings quote ounces per square yard, mills quote grams per square metre. The conversion is fixed: 1 oz/yd² = 33.9 g/m². A 4.3 oz tee is about 146 GSM, a 5.3 oz tee about 180 GSM, a 6.0 oz tee about 203 GSM.
oz/yd²
GSM
What it is normally used for
3.6–4.2 oz122–142 gsm
122–142 gsm
Summer and fashion tee. Drapey, close to sheer in light colours.
4.3 oz146 gsm
146 gsm
Light retail tee. Common for tri-blends and softer programmes.
4.5–5.0 oz153–170 gsm
153–170 gsm
Around the 160 GSM weight most of the world sells.
5.3 oz180 gsm
180 gsm
Premium retail. Structured, opaque, keeps its shape.
6.0 oz203 gsm
203 gsm
Heavyweight retail — the current streetwear default.
6.5–7.0 oz220–237 gsm
220–237 gsm
Boxy streetwear. Stands away from the body.
7.5 oz +254 gsm +
254 gsm +
Specialty heavy. Slow to dry, expensive to ship.
Fibre and yarn
Same weight, different yarn.
Yarn count (Ne)
Higher Ne means finer yarn. 30s is the standard tee count — the same 180 GSM knit in 30s is denser and smoother than in 20s.
Ring-spun vs open-end
Ring-spun twists slower: softer, stronger, less hairy. Open-end rotor is faster and cheaper, and you can feel the difference on the surface.
Combed vs carded
Combing removes short fibres — roughly 12–20% of the weight — before spinning. Less pilling and a smoother hand, at a higher fibre cost.
This is why a “180 GSM combed ring-spun” tee and a “180 GSM open-end carded” tee can be quoted far apart and still both be honestly described. Neither is a lie — they are different garments wearing the same weight.
Construction
How the body is built.
A tubular tee is cut from a body knitted as a continuous tube: no side seams, fewer operations, lower cost. A side-seamed tee is cut as separate front and back panels and joined down each side. Three things change:
Torquing
Single jersey knitted in the round carries residual twist, so the side of the garment rotates after washing. Trade guidance treats more than about 5% displacement as a failure. Side seams hold it straight.
Fit
Tube diameters come in machine steps, so sizes jump unevenly — and a tube cannot have a shaped armhole or a graded neck opening.
Printing
Side seams give a press operator a straight edge to register against, which speeds set-up and keeps placement consistent across a run.
Tubular is not automatically wrong — it is the traditional build for a boxy heavyweight, and on a short run of one-colour front prints the fit penalty may not matter to you. The point is to know which one you bought, because it decides how the garment behaves after ten washes.
Shrinkage
Pre-shrunk is a process, not a promise.
Untreated 100% cotton jersey shrinks 5.0–7.5% in the first home wash. Mechanical compacting brings it into the ±3% tolerance most brands write on the label. That is why “pre-shrunk” on its own tells you a process happened, not how much the garment will move.
The measurement matters as much as the number: shrinkage is tested under AATCC TM135 in a North American top-loading machine, or ISO 6330 in a European front-loader. The two are not interchangeable. A supplier quoting an ISO figure against your AATCC spec has answered a different question — ask which standard a percentage was measured under before you compare it with anything.
Details
The three that outlive the trend.
Neck
Ask for rib weight, taping and seam type. Shoulder-to-shoulder tape is the cheapest visible indicator of a garment built to hold its shape.
Hems
Single-needle versus coverstitch. A cheap hem at the sleeve and bottom is the first thing to ripple, usually by the fifth wash.
Label
Tearaway or sewn-in. A tearaway saves you a relabelling operation on every piece you decorate — a sewn-in one has to be picked out.
Fit
Fit is the block, not the weight.
Weight and yarn describe the fabric. The block — the pattern underneath — describes the garment, and it is the one thing you cannot change later. Classic blocks run longer with a fuller sleeve; modern retail blocks are trimmer through the body with a shorter sleeve; boxy streetwear blocks are wide against their length with a dropped shoulder.
Every brand grades to its own block, so a size name does not travel. Compare four numbers in the size you sell most, for the exact style number: chest one inch below the armhole, body length from the highest point of shoulder, sleeve length and shoulder width. Two minutes with those four numbers tells you more than any description of how the fabric feels.
Our sheets
What our spec sheets cover.
Every style we sell has a one-page A4 spec sheet, and it covers six of the fields above: finished weight in GSM with the ounce conversion, composition, construction and fit, the full size table measured flat in centimetres with inches underneath, the colours that style is cut in, and each print area with its code.
It does not cover yarn count, shrinkage results or label type. We would rather leave those blank than print a number nobody on the floor has confirmed — ask for a style and we will get the figure from production instead of guessing.
Questions
The four that come up most.
Why does the same 180 GSM fabric feel different on two suppliers?
Because weight is only one field. Yarn count, ring-spun versus open-end, combed versus carded and the fit block all change how 180 GSM feels. Ask for those four before comparing prices.
Is a heavier blank always better?
No. Weight is a decision, not a quality score. A 146 GSM tee is the right answer for a summer drop; a 203 GSM tee is the right answer for a boxy streetwear silhouette. What matters is that the number is the finished weight and that it matches what you are printing.
Why do two suppliers quote shrinkage differently?
Because the test is different. AATCC TM135 (North American top-loading machine) and ISO 6330 (European front-loader) are not interchangeable, so ask which one a figure was measured under before you compare it with your own spec.
What should I ask for if a spec sheet has no size table?
Ask for points of measure for the exact style number: chest measured one inch below the armhole, body length from the highest point of shoulder, sleeve length and shoulder width. Brand size names do not travel between suppliers.
Where the numbers come from
The figures on this page are published industry references, not our own estimates: the ounce conversion (1 oz/yd² = 33.9 g/m²), fabric mass measured per ASTM D3776 on finished, conditioned fabric, dimensional change tested under AATCC TM135 or ISO 6330, and manufacturer guidance on torque tolerance. Where trade sources give a range we quote the range.
Send us the spec you need.
Tell us the weight, the fit, the colours and where you print — we will tell you which blank matches, and what the sheet says for that style.