Choosing the Right Fabric GSM and Blend for Your Garment
"Premium cotton" on a spec sheet doesn't tell a factory much on its own. Two numbers, GSM (grams per square meter) and blend ratio, do most of the work in defining how a fabric will actually feel, drape, and hold up, and they're worth understanding before you finalize a tech pack.
What GSM actually tells you
GSM measures fabric weight per square meter, which correlates with thickness, opacity, and how substantial a garment feels. It isn't a direct measure of quality; it's a measure of density, and the right GSM depends entirely on what the garment is for.
- 140-180 GSM: lightweight, better for warm-climate basics and summer tees; drapes more, shows more see-through risk on lighter colors.
- 180-220 GSM: the common mid-weight range for everyday t-shirts and polos; a reasonable balance of structure and comfort.
- 220-280 GSM: heavier, more structured; typical for premium streetwear tees and mid-weight sweatshirts.
- 300 GSM and above: heavyweight fleece and hoodie territory; substantial hand-feel, less drape, warmer.
What blend ratio changes
- 100% cotton: soft hand-feel and breathable, but shrinks more and wrinkles more than blended fabrics, and has less recovery after stretching.
- Cotton-polyester blends: more dimensionally stable, wrinkle-resistant, and often more colorfast in printing, at some cost to natural-fiber feel.
- Cotton-modal or cotton-viscose blends: adds drape and a softer, slightly silkier feel, common in premium basics.
- Performance polyester and spandex blends: moisture-wicking and stretch recovery, standard for sportswear and activewear rather than casual basics.
Matching fabric choice to the print method
Fabric and customization method aren't independent decisions. Sublimation needs a high polyester content to take the dye properly; it won't work well on 100% cotton. Screen printing and embroidery are largely fabric-agnostic, but heavier GSM fabrics hold embroidery stitch density better than very lightweight ones.
What to specify in a tech pack
- Target GSM range, not just a fabric name -- "cotton" alone leaves too much room for interpretation.
- Blend ratio if it matters to feel or performance, not just fiber type.
- A physical swatch or reference garment where possible; a fabric photo alone doesn't convey hand-feel or weight.
Beyond Detail sources and lab-dip matches fabric in-house across cotton, cotton blends, and performance polyester, and can recommend a GSM and blend starting point during tech-pack review.