What grams per square metre means
Short answer: The number tells you how much one square metre of the fabric weighs. It is the best single figure for judging whether a fabric is thin or full. Here is a simple guide to reading it and to what it means for your clothes day to day.
What the number is
Grams per square metre, often written g/m², is the weight of the fabric over an area of one metre by one metre. The number says nothing about colour or pattern, but it tells you a lot about how dense and thick the fabric is. That is why it works as a shared yardstick for comparing textiles.
How to read the number
The number works as a rule of thumb. Under 140 grams is a thin fabric that suits summer. Between 140 and 180 grams sits an ordinary T-shirt. Over 200 grams is a fuller fabric. These are not fixed limits, but they give a good picture of what you can expect.
Thin summer fabric
A fabric under 140 grams is light and airy, and it often feels cool on a warm day. On the other hand it can be easier to see through, and it does not stand up to as much wear as a heavier fabric. It suits hot weather, but is a less obvious choice if the garment must last for years.
The ordinary T-shirt
Most T-shirts sit between 140 and 180 grams. That weight feels comfortable without seeming heavy, and it works both as a single layer and under a shirt or jumper. If you are unsure, this is the range where you rarely go wrong for everyday use.
The fuller fabric
Fabrics over 200 grams are used for sweatshirts and better basics, where you want a little more body. They give more warmth and more substance, and the garment often hangs better. In return it is warmer to wear, so it suits cooler days best, or anyone who likes fuller garments.
Why the number matters
Two garments with the same fibre blend can feel very different if the weight differs. A bamboo T-shirt of 150 grams and one of 220 grams are not two versions of the same thing. Weight is therefore at least as important as the fibre when you judge a purchase. See bamboo clothing for men.
Transparency, warmth and durability
Weight decides three things you notice at once: how much the fabric shows through, how warm it is and how long the garment lasts. A heavier fabric is less see-through, warmer and usually more hard-wearing. A lighter fabric is cooler, but may wear through sooner, especially if you wash it often.
Where to find the number
Some shops state the fabric weight in the product description, but not all do. If you cannot find the figure, look at how the fabric is described and how thick it sounds. For example, compare bamboo tops for women and bamboo training clothes for women.
How big a difference you can feel
Ten grams is such a small difference that few people notice it. Thirty grams is another matter, and you can clearly feel it in the hand and on the body. When you compare two garments, it therefore makes more sense to look at large differences in weight than at small numbers that sit close together.
Frequently asked questions
Does a higher weight mean better quality
Not in itself, but a heavier fabric usually lasts longer, because there is more material to stand up to wear. Quality also depends on the fibre, the weave or knit and how the garment is sewn.
What is a good weight for a T-shirt
Between 150 and 180 grams suits most people for an ordinary everyday T-shirt. If you want something cooler for summer you can go a little lower, and for more body you can go a little higher.
Can you feel the difference of ten grams
Rarely, because ten grams is a very small difference in a fabric. Thirty grams is clearly noticeable, both when you hold the fabric in your hand and when you wear it all day.
You can find the full range at Bamboo-Clothing.com.
