Tech Pack Guide

Tech Pack for Oversized T-Shirts: Measurements, Fabric & Build Specs

Your oversized tee lives or dies at the measurement chart. A 2 cm difference in shoulder drop turns a clean streetwear silhouette into something that looks accidentally large. A 200 GSM fabric drapes; a 240 GSM stands. Whether you nail it depends on your tech pack — the document your manufacturer reads before cutting a single stitch.

This guide covers everything your tech pack needs for an oversized t-shirt: standard measurements across sizes, fabric weight recommendations, the construction details factories actually care about, and the mistakes first-time brand founders make.

You don't need a fashion degree to write one. You need clarity on what factories want to see — and a way to put it on paper without guessing.

Skip the manual work. tpack pre-fills the oversized tee baseline and exports a factory-ready PDF in 15 minutes — €15.

Try it free →

What makes an oversized tee “oversized”

Oversized isn't just “bigger.” A correctly designed oversized tee combines four signature traits that work together to create the streetwear silhouette:

  1. Dropped shoulders. The shoulder seam sits below the natural shoulder line — usually 3–6 cm past it. This creates the relaxed, slouchy look, but it means the sleeve has to be redrafted entirely. You can't just enlarge a regular pattern.
  2. Extended body width. Wider chest measurement, typically 6–10 cm more than a regular tee at the same nominal size. That extra room is what gives the boxy drape.
  3. Longer length. The body extends past the hip bone, often hitting mid-hip or below.
  4. Heavier fabric (usually). Premium oversized tees lean toward 220–260 GSM. The weight is what makes them drape with structure rather than balloon out.

Miss any of the four and you get something that looks accidentally big rather than intentionally oversized.

Standard measurements for oversized tees

These are typical finished-garment measurements for streetwear oversized tees. Use them as a baseline; your fit might shift them by 1–2 cm in either direction.

SizeChest (flat)Body lengthShoulderSleeve
S56 cm72 cm56 cm24 cm
M59 cm74 cm59 cm25 cm
L62 cm76 cm62 cm26 cm
XL65 cm78 cm65 cm27 cm
XXL68 cm80 cm68 cm28 cm

Two things to add to your tech pack on top of the chart:

  • Measurement points. Always specify where you measure — for example, “chest measured 2.5 cm below the armhole, garment flat” rather than just “chest.” Factories interpret ambiguity their own way.
  • Tolerances. State acceptable variance: ±0.5 cm for small measurements, ±1 cm for body length. Without this, you have no grounds to reject samples that are off.

These are finished garment measurements — what the tee measures when laid flat after construction. Your factory translates them into patterns. Don't confuse them with body measurements.

Recommended fabric weights

Fabric weight — measured in GSM (grams per square meter) — is the single biggest factor in how your tee feels, drapes, and reads on camera. Three buckets to know:

180–200 GSM — Lightweight oversized

Drapes more, less structure. Good for summer drops and softer aesthetics. Cheaper to produce. Works if you want a relaxed feel, but the silhouette won't hold its shape on the body.

220–240 GSM — Premium streetwear standardRecommended

The sweet spot for oversized tees. Holds shape, drapes structured, reads premium. This is where most well-regarded streetwear brands sit. 240 GSM specifically is the go-to weight for “boxy” and “oversized” fits that need a crisp drape.

260 GSM+ — Heavyweight oversized

Boxy, sculptural drape. Holds its shape almost independently of the wearer. Reads expensive, but adds production cost, shipping weight, and warmth — not ideal for warm climates or summer drops.

Fiber composition

  • 100% combed cotton, ring-spun — Best general choice. Softer than open-end, more durable, takes prints cleanly.
  • 90/10 cotton/polyester — Reduces shrinkage and slightly improves wrinkle resistance. Useful at scale when fabric consistency matters.
  • Avoid 100% polyester for streetwear unless you want a specific performance feel. It reads as cheap or technical.

Tech pack format for fabric spec: 240 GSM, 100% combed cotton, ring-spun, jersey knit, garment-washed

Construction details that matter

Eight construction decisions your manufacturer needs spelled out. Skip these and you'll get back a sample that's “close but not quite” — and a second sample round will cost you another two to four weeks.

  1. Side seam vs tubular. Side-seamed construction lets you control the fit precisely. Tubular (no side seam) is cheaper but limits how clean the oversized silhouette looks. Streetwear nearly always uses side seams.
  2. Neckline rib. Specify the rib type (1×1 or 2×2), width (typically 1–1.5 cm), and that it should be the same fabric/dye lot as the body.
  3. Shoulder taping. Twill tape inside the shoulder seam adds durability and holds the shoulder line straight. Standard on premium tees, skipped on budget production.
  4. Stitch type. Cover stitch (double needle) at the hems looks more premium than single needle. Specify which goes where: cover stitch for body hem, sleeve hem; lockstitch elsewhere.
  5. Stitch density (SPI). Stitches per inch. 10–12 SPI is standard for tees. Under 10 looks cheap; over 14 reads as fast fashion.
  6. Hem allowance. Typical 2–2.5 cm for the body hem, 2 cm for the sleeve hem.
  7. Label placement. Inside-back-collar (standard woven label) vs side-seam (often a printed brand label). Specify exact placement in cm from a reference seam.
  8. Garment-wash / pre-shrink. Without this, your tees shrink 3–5% after the customer's first wash. Always specify “garment-washed” or “pre-shrunk” in the tech pack.

Four mistakes first-time founders make

After reviewing dozens of first-attempt tech packs, the same four mistakes show up over and over:

1. No grading specs

Founders give one size's measurements and expect the factory to figure out the rest. Manufacturers will guess — and they'll guess differently than you would. Always give measurements for every size you're producing.

2. Mixing cm and inches

Some measurements in cm, others in inches — often because labels get written in inches out of habit. Pick one unit, use it everywhere on the document.

3. Vague fabric reference

Writing “cotton” or “soft cotton” tells the factory nothing. Specify GSM, fiber content, weave, treatment — and ideally a supplier reference if you have one.

4. No tolerances

Without explicit tolerance specs (±0.5 cm, ±1 cm), factories use their own — which may be looser than you'd accept. State tolerances in the tech pack and you have grounds to reject off-spec samples.

Building one in tpack

A tpack oversized-tee tech pack takes about 15 minutes:

  1. Pick “T-shirt” → “Oversized fit.” The tool pre-fills the standard oversized baseline measurements, which you can edit per size.
  2. Add your specs: chest/length adjustments, fabric (with a GSM slider), color (Pantone or hex), print placements, label spec.
  3. Review the auto-generated technical flat showing front, back, and measurement arrows.
  4. Export the PDF: cover page, spec sheet, BOM, construction notes, labels page — all in factory-standard format.

You get a tech pack your factory can quote from on day one — without paying a designer €200–€300 to assemble it.

Frequently asked questions

Do I need pattern grading specs?

Yes, if you're producing more than one size. Factories need the exact deltas between sizes. tpack auto-grades when you give base measurements — you can override per size if needed.

My measurements differ from the standards above. Is that okay?

Completely fine. The chart is a baseline, not a rule. The point is consistency: pick your measurements, write them down, hold the factory to them.

Will manufacturers accept a tpack PDF?

Yes — the PDF follows standard tech pack conventions (cover with flats, spec sheet, BOM, construction notes, labels page) that factories in Portugal, Turkey, Vietnam, and Bangladesh recognise.

How detailed do I need to be for the first prototype?

Core measurements, fabric, and key construction notes are enough for a first sample. You iterate from what comes back. Going into extreme detail before seeing a real sample usually wastes effort.

What if I want a non-standard detail like asymmetric hems?

Add it as a construction note with a sketch or reference image. The tech pack's job is to remove ambiguity — anything that can be misinterpreted should be illustrated.

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