GSM stands for grams per square meter, and it is a unit of measurement that determines the weight of a fabric in relation to how much space it takes up. The higher the number, such as 400, means that it is heavy and takes up more space. For example, cotton has a low GSM which means that it is light and takes up less space than wool because fewer fibers are woven together. Different fabrics will have different GSM and, as a consequence different applications.
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The importance of gsm in fabric
GSM, or grams per square meter, is the unit of mass used to define the weight of fabric like polyester or cotton and other materials such as paper. It describes how heavy the material is for its actual size. For example, if you have two pieces of cloth that are both 1 yard (0.9144 meters) in length and one is made from rayon and weighs 8 ounces (227 grams) and another made from cotton and weighs 10 ounces (283 grams), then the rayon cloth has a higher gsm than the cotton cloth; it would be labeled as 90g/m2 while the cotton cloth would be labeled as 100g/m2. GSM can also be used when describing the weight of other materials, such as paper.
As a fabric’s gsm increases, so does its density. A high GSM means that the cotton used is more tightly woven and thus has less breathability than a lower GSM fabric. If you are outdoors in hot weather or exercising, higher GSM fabrics can make you too warm if not combined with cooling features like vents at the armpits or back of the garment. Lower GSM fabrics will usually feel softer against your skin. Higher gsm levels are often associated with better protection from ultraviolet radiation because they block out more light; however, higher gsm also means less air between the threads to absorb sweat away from your body to evaporate. If you sweat a lot, opt for clothes made from lighter-weight fabrics such as cotton because they soak up and evaporate sweat better than high-density fabrics that leave human skin wet and clammy.
The higher the GSM of a fabric, the more durable it is and the stronger it feels. High gsm weight fabrics are less likely to rip or snag than lower gsm ones. The GSM is increased by adding more fiber content to thicker fabrics; this also makes them stiffer because there’s more material compacted within each square inch. Loose weave like gauze weighs less than tight weave like poplin (likewise, poplin weighs much less than denim).
I recommend lightweight cotton for summer and a mid-weight cotton-polyester blend for winter.
What is a good fabric GSM?
As stated above, a higher GSM number means a heavier and thicker fabric, and a lower number means a lighter and thinner fabric. For example, 400gsm (grams per square meter) refers to an average thickness, while 160gsm refers to something slightly thinner than average. Here are some guidelines when using gsm as your guide:
1. The higher the gsm number, the more coverage you’ll get from it, so it may be advisable for window treatments where light control is required, such as curtains and draperies, especially if you would like them to hang full.
2. If you would like your curtains to be full and drape well, fabrics with a weight of 250 gsm or more are advisable. These will also give you ample insulation during colder seasons. When it comes to lightweight fabrics, most people prefer 100 gsm or less since they can simply hang them on rings without worrying that light will pass through.
3. Fabrics with lower gsm numbers tend to wrinkle easier than those with higher ones. If this is not an issue for your project then it’s really up to what you prefer, especially when choosing what type of fabric to use in light of the project you wish to accomplish: drapery paneling or window treatments where weight is a secondary consideration after styling.
Is 300 GSM fabric thick?
Heavy fabrics such as those with weights ranging between 300 to 350 GSM usually manufacture winter wear like coats and jackets. These garments often include high-end finishing such as lining, fur collars, and pockets, contributing to their high prices. Cotton fabric usually runs around 200-280 gsm, whereas silk can reach as high as 800+ gsm. By comparison, most apparel fabrics are between 110 to 160 gsm. Synthetic fabrics tend to run on the lower end of that spectrum, though some outdoor performance clothing may be over 200 gs to protect from wind and rain. Fabrics below 100 gsm are considered sheer or very lightweight. Such a fabric would not make a good winter coat without lining, for example—it still needs a little body so it won’t swish around too much in a blustery winter wind.
Is 180 GSM fabric good?
180 GSM fabric is best suited for blending or single jersey. Blended fabrics give garments the feel and comfort of cotton at a much lower price point. Single jerseys are lighter weight and more versatile than comparable 100% cotton fabric, but less expensive than knits like interlock and rib-knit.
250 GSM fabric applications
250 GSM fabric is extremely soft and provides great drape on woven apparel items; it has an almost liquid appearance to the imagination. It also works perfectly as a blouse fabric or lightweight, pocketed t-shirts.