GSM—grams per square meter—is the single most important number in menswear that most men have never heard of. It determines how a garment feels against the body, how it drapes, how long it lasts, and whether it holds its structure after a hundred washes. Understanding GSM is the difference between buying a hoodie and investing in one.
What GSM Actually Measures
GSM is a standardized measurement of fabric weight. A single square meter of the fabric is weighed, and that number is its GSM. The higher the number, the heavier and denser the fabric. A standard supermarket t-shirt sits around 140-160 GSM. A fast fashion hoodie typically falls between 240 and 280 GSM. A garment worth owning starts at 320 GSM and above.
Weight is not the only variable—fiber composition, construction method, and finishing all affect the final hand-feel—but GSM is the most reliable indicator of substantiality before you ever touch the fabric.
Why Lightweight Feels Cheap Over Time
Low-GSM garments degrade quickly. The fibers are less densely packed, which means they pill faster, lose their shape under repeated tension, and fade unevenly with washing. A 180 GSM t-shirt worn weekly will look exhausted within six months. The structural failure is not just aesthetic—the garment is literally coming apart at a microscopic level from the first wash.
This is why price per wear is a more honest metric than retail price. A 25 GBP hoodie at 260 GSM that lasts eight months costs more per wear than a 135 GBP hoodie at 480 GSM that lasts four years.
The Calton Brown Standard: 320 GSM and Above
Every piece in the Calton Brown core range is built to a minimum weight threshold that reflects the brand's position on permanence. The Uniform Heavyweight Base is constructed at 320 GSM—dense enough to hold a structured drape without becoming rigid. The Phantom Patina Hoodie operates at 480 GSM, placing it in a category occupied by workwear and military-grade fleece, not fashion.
The Heritage Zip Hoodie sits at 410 GSM with a dual-zip closure built from hardware that matches the weight of the fabric. Every component decision is made at the same standard.
GSM by Category: What to Expect
T-shirts and base layers: 180-220 GSM is standard market weight. 280-320 GSM is premium. 320 GSM and above are considered heavyweight foundation grade.
Hoodies and fleece: 280-320 GSM is the mass market. 380-420 GSM is the premium bracket. 480 GSM and above represents a deliberate architectural commitment to weight as a design principle.
Trousers and denim: 14 oz and above qualifies as rigid heavyweight denim. The Relic Denim is constructed from 14 oz. Italian mill denim—dense, structured, and built for permanence.
Outerwear: The Atmospheric Baffle Parka uses a high-loft baffle construction that prioritizes insulation volume alongside outer shell density.
How to Read a Product Description for GSM
When a brand lists GSM in their product descriptions, they are making a commitment. When they do not, they are hiding something. The absence of GSM data in a menswear product description is one of the clearest signals that the garment does not benchmark well against what the price implies.
At Calton Brown, GSM is listed where it is a primary construction specification. It is not a marketing number. It is the starting point of every product decision.
Building Around Weight
The most considered wardrobes are built around pieces that justify their place through construction, not trend. GSM is one of the most honest tools a man has for evaluating whether a garment earns its space in his wardrobe before he buys it. Explore the full Calton Brown range and look for the weight specification on every product page.
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