Fabric Guide
The Heavyweight Hoodie Guide
A heavyweight hoodie is defined by its fabric weight, not its look. Where a standard high-street hoodie uses fleece around 280 to 320 gsm, a true heavyweight hoodie starts at roughly 400 gsm — and ONETHANZERO hoodies are built at 550 gsm.
This guide explains what gsm means, how heavyweight cotton fleece is constructed, why it wears better over time, and how to choose and care for one.
What Does GSM Mean?
GSM stands for grams per square metre — the weight of one square metre of fabric. It is the single most reliable measure of how substantial a hoodie will feel and how it will hold its shape.
Lightweight hoodies sit around 200 to 280 gsm. Midweight hoodies — the majority of the market — sit between 280 and 350 gsm. Anything above 400 gsm is considered heavyweight. At 550 gsm, the fabric is dense enough to stand away from the body, drape cleanly, and resist the sagging and twisting that lighter fleece develops after repeated washing.
Why 550 GSM Cotton Fleece
ONETHANZERO hoodies use 100% heavyweight cotton fleece at 550 gsm, with a brushed fleece interior. The outer face is tightly knitted for a smooth, structured surface; the inside is brushed to raise the fibres into a soft, insulating pile.
The result is a hoodie that feels substantial from the first wear, holds heat without bulk from synthetic padding, and softens with age rather than thinning out.
- 100% heavyweight cotton — no polyester filler
- 550 gsm dense-knit outer face
- Brushed cotton fleece interior for warmth and softness
- Ribbed cuffs and waistband that recover their shape
Construction Details That Matter
Fabric weight alone does not make a heavyweight hoodie. The construction has to support it:
- Double-layer hood — two layers of the same 550 gsm fleece, so the hood holds its shape and sits properly
- Dropped shoulders and an oversized fit, cut to drape rather than cling
- Reinforced stitching at stress points — shoulders, cuffs, kangaroo pocket
- Premium embroidery and high-density woven labels instead of prints that crack
- Ribbed cuffs and waistband with enough tension to anchor the weight of the fabric
Heavyweight vs Regular Hoodies
A regular hoodie is lighter, cheaper to produce, and easier to layer — but it loses shape faster, pills sooner, and offers less warmth per layer. A heavyweight hoodie is an outerwear-grade garment: warmer, more structured, and built to be worn for years.
If you want a hoodie that looks the same in year three as it did in week one, fabric weight is the specification to check first.
How a Heavyweight Hoodie Should Fit
ONETHANZERO hoodies are cut oversized: dropped shoulders, a roomy body, and a hem that sits at the hip. Take your usual size for the intended oversized drape, or size down if you prefer a closer fit.
Because 550 gsm fleece has very little stretch, the fit comes from the cut rather than the fabric — check the measurements in our Size Guide before ordering.
Caring for Heavyweight Cotton
Heavyweight cotton fleece rewards simple care. Wash inside out at 30°C with similar colours, avoid tumble drying where possible, and reshape while damp. The fabric will soften and develop character with each wash without losing its structure.
Shop ONETHANZERO Heavyweight Hoodies
Every ONETHANZERO hoodie and sweatshirt is made to the specification in this guide — 550 gsm heavyweight cotton fleece, oversized fit, designed and assembled in London.