Fit

How to Read Fabric Weight When Buying Online

Buying a shirt online means judging fabric you cannot touch. The photos show color and cut, but the thing your hands would check first in person, how the fabric feels and falls, has to be read from the listing instead. The good news is that listings say more than most people realize, once you know which numbers and words to look at.

This guide covers the three skills that close the gap: reading fabric weight, using flat measurements instead of size labels, and decoding fiber descriptions.

GSM: the number that describes the feel

Fabric weight is measured in grams per square meter, written as GSM. It is the closest thing a listing has to letting you touch the fabric, because weight predicts drape, opacity, and how the shirt will sit on the body.

• Under 140 GSM is lightweight: airy, softer drape, and often slightly sheer in pale colors. Suited to hot days and layering.
• 140 to 180 GSM is the everyday middle: opaque, holds its line without stiffness, and works across most of the year. Most well-made everyday shirts live here.
• Over 180 GSM is substantial: a boxier, more structured hang, more warmth, and a fabric that reads as sturdy the moment you pick it up.

Neither end is better. A 120 GSM shirt and a 200 GSM shirt are different tools. What matters is knowing which one you are ordering, so the parcel matches the picture in your head. When a listing skips GSM, words carry the same signal: gauzy, airy, and featherweight sit at the light end, while midweight, dense, and structured sit at the heavy end.

Trust flat measurements, not the size letter

A size letter is a label. A flat measurement is a fact. Two shirts marked the same size can differ by several centimeters in the chest, because sizing conventions vary between makers and between cuts. The measurements published with each item describe that specific shape, which is why they are the thing to go by.

The method takes two minutes. Take a shirt you already own and love the fit of, lay it flat and smooth, and measure across the chest just under the sleeves, across the shoulder seam to seam, down the back from collar base to hem, and along the sleeve. Compare those four numbers to the listing. When they land within a couple of centimeters of your reference shirt, the fit will feel familiar out of the parcel, whatever the size letter says.

Reading fiber content like a native

The fiber line tells you how the shirt will behave, wash after wash, if you know its habits:

• Cotton is the all-rounder: soft, sturdy, easy to wash, and it settles into itself with wear. Long-staple cottons feel smoother and resist pilling.
• Linen runs cool and dries fast, with a dry, textured hand. It creases as a matter of character, and the crease is part of the look rather than a flaw.
• Cotton-linen blends split the difference: most of linen’s airflow with less of its wrinkle, and a texture that reads relaxed rather than rumpled.
• A small synthetic percentage, a few percent of elastane for example, adds stretch and recovery. In modest amounts it helps a shirt keep its shape.

The signals that a fabric will hold its shape

Some listings tell you about year two, not just day one, and those phrases are worth hunting for. Pre-shrunk or pre-washed means the shrinking already happened at the factory instead of in your machine. A tighter weave and a mid or heavier GSM resist bagging at the elbows. Ribbed or reinforced collars are the difference between a neckline that sits flat in year two and one that ripples after a season.

Construction details finish the picture: double stitching at the shoulders and sides, clean hems, and a description that names its materials plainly instead of hiding behind adjectives. Listings that publish GSM, flat measurements, and fiber content are doing the work a fitting room would, and that is the standard we hold our own listings to in the Teehog shop. Once the right shirt arrives, keeping it in shape is the easy part, and our 20-wash care routine walks through exactly that.