Apparel · Materials · Specifications
How to Read Garment Specs Like a Supplier Drawing
Two tees can look identical on a product page and feel completely different once they land on your desk chair or shop floor. The print gets your attention; the blank garment decides whether the shirt stays in rotation or sinks to the bottom of the drawer.
A garment spec is a bill of materials, process notes and acceptance criteria for something you wear. Read it with the same healthy suspicion you'd bring to a supplier drawing that says "close enough".
> Key takeaways
- Fiber content is material selection, not performance: yarn, knit, weight and construction decide how the shirt behaves.
- Fabric weight (g/m² or oz/yd²) predicts feel and warmth, but a dense, well-knit light fabric can outlast a loose heavy one.
- Size labels are categories, not dimensions. Compare the measurement chart with a shirt you already wear.
Fiber content: material selection, not performance
The first line most people read is fiber content: 100% cotton, cotton-poly, tri-blend, organic cotton. In the EU and the US, fiber names on labels are regulated. The line tells you what the fabric is made of. It doesn't tell you how the shirt will feel, fit or age.
Natural hand
100% cotton
Breathable, familiar feel, a good base for graphic prints. Can shrink, wrinkle and dry slowly. Quality depends on yarn, knit and finishing.
Shape retention
Cotton-poly blend
Polyester improves shape retention and drying time and reduces shrinkage. Less natural feel, and a different surface for ink.
Drape
Tri-blend
Usually cotton, polyester and rayon, chosen for softness and drape. Soft out of the box does not mean more durable.
Provenance
Organic cotton
Describes how the cotton was grown. It says nothing about weight, softness or construction, so read the rest of the spec.
Fabric weight: GSM vs oz/yd²
Weight is given in grams per square meter (GSM) or ounces per square yard. It's the fastest way to predict how a shirt will feel before you touch it. The conversion is simple: 1 oz/yd² ≈ 33.9 g/m².
| Class | oz/yd² | g/m² | Behavior |
|---|---|---|---|
| Lightweight | 3.5–4.5 | ~120–150 | Breathable, easy to layer, drapes close to the body, less structure |
| Midweight | 4.5–6 | ~150–200 | The practical middle: substance without turning a warm day into a heat test |
| Heavyweight | 6+ | ~200+ | Holds its shape, feels substantial, runs warmer and stiffer until broken in |
Weight alone doesn't equal quality. A dense, well-knit 4.3 oz tee can outlast a loosely knit 6 oz one. Treat GSM as one dimension on the drawing, not the complete part spec. If you want the trade-offs in detail, see heavyweight vs lightweight tees.
Yarn and knit: ring-spun, combed, open-end
When a spec lists yarn and knit details, it's giving you the process, not just the material.
- Combed cotton: short fibers and impurities are combed out before spinning, leaving longer, more aligned fibers.
- Ring-spun cotton: the yarn is twisted and thinned continuously, giving a finer, smoother yarn. Smoother surface usually means a softer hand and sharper print edges.
- Open-end cotton: faster, cheaper spinning that gives a more textured, slightly coarser yarn. Classic budget workwear feel.
- Jersey knit: the standard T-shirt structure, stretchy across the width. Two jerseys with the same fiber content can behave very differently depending on yarn and density.
As a reference point, our standard tees are Bella+Canvas blanks in Airlume combed and ring-spun cotton. That line on the spec is why the surface is smooth enough to hold fine technical line work.
// related gear QA Compliance MantraQA Compliance Mantra TeeConstruction: where the shirt earns its keep
A product page that gives only color and a clever graphic is leaving out the useful data. Construction details tell you whether the garment was designed for repeated use and laundering.
// Construction checklist
None of these is a durability certificate. But they're better evidence than adjectives like "premium".
Fit specs: measurements beat size labels
A size L is not a controlled dimension. It's a category, and one brand's large can be another brand's medium once cut and shrinkage are involved.
The useful numbers are garment measurements: chest width (measured flat, armpit to armpit), body length and sleeve length. Double the chest width for an approximate circumference. Then compare with a shirt you already own and wear often, not just with your body measurement, unless you know how much ease you like.
Fit names such as retail, classic, relaxed or slim are a starting hypothesis. The measurement chart is the inspection report. A chart tolerance of about ±1 in (±2.5 cm) is normal in cut-and-sew production: soft goods are not ground shafts. Our fit guide walks through the measurements.
Print method and care are part of the spec
On graphic apparel, the print is a surface treatment with its own requirements. Screen printing lays down a thick, opaque ink layer that suits bold graphics. Direct-to-garment (DTG) prints the design into the fabric surface with water-based inks and handles fine detail and gradients well; its durability depends on pretreatment, curing, fabric and washing. Our designs are printed on demand with DTG. The screen print vs DTG comparison covers the trade-offs.
Read the care instructions as process control, not fine print. Inside out, moderate temperature, air dry or low heat, no iron directly on the print. For our tees that means 30 °C maximum; the cotton care page has the full procedure.
// grabnade.com · apparel
Measure Stuff. Super Effective.
For the person who reads the size chart before the product description, and checks it against a caliper anyway.
The takeaway: read it as one system
There's no single best shirt, only the right one for the application. A lighter cotton tee for a warm production floor, a heavier tee or a hoodie for a cold shop. Read fiber content, weight, yarn, construction, measurements and care together, the way you'd review a drawing: one bad dimension can sink an otherwise good part.
A good spec sheet won't tell you whether a shirt becomes your favorite. It tells you whether that outcome is plausible before you spend the money, which beats trusting a product photo shot under unusually forgiving lighting. More designs for spec-minded people are in quality engineer t-shirts.
FAQ
What does GSM mean on a t-shirt?
Grams per square meter: the fabric's weight per unit area. Around 120–150 g/m² is lightweight, 150–200 midweight, 200 and up heavyweight. Multiply oz/yd² by about 33.9 to convert.
Is a heavier t-shirt better quality?
Not automatically. Weight predicts feel and warmth. Durability also depends on yarn, knit density and construction, so a dense lightweight tee can outlast a loose heavyweight one.
What is combed ring-spun cotton?
Cotton combed to remove short fibers, then spun by continuous twisting into a fine, smooth yarn. It usually gives a softer surface and cleaner print edges than open-end cotton.
How do I choose a size without trying the shirt on?
Lay a shirt you like flat, measure chest width and body length, and compare with the brand's measurement chart. Allow for normal production tolerance of about an inch.
Sources and standards
- ASTM D3776/D3776M — Standard test methods for mass per unit area (weight) of fabric
- Regulation (EU) No 1007/2011 — Textile fibre names and labelling of fibre composition
- ISO 3758 — Textiles, care labelling code using symbols
About the author
Gabriel Weider is a mechanical engineer with 15 years in special machines, CAD, medtech and regulated environments. He still works full-time as an engineer and designs every grabNade shirt. Read his story.