January 26, 2019 Ian Rammelkamp

What is GSM?

What does GSM mean in fabric? GSM stands for Grams per Square Meter (g/m²). It is the weight of the fabric if you take a sheet of material which is one meter by one meter square and weigh it in grams.

It is a bench mark specification to meet production manufacturing requirements. It is also a standard (one of many) upon which different materials are compared.

When we design a new product we have a GSM target depending on the products use, the weave, and the required cost.

When we do quality control (during and after production) we weigh the material to make sure that it meets the target GSM (within tolerances).

Normal tolerance for GSM is +/- 3%. So a 300 GSM material can vary in weight between 291 and 309 GSM.

Is a higher GSM better?

No. Although many marketing companies will have you believe that higher GSM is better.

All else being equal, higher GSM towel have more more microfiber, and are therefore more expensive. It will also be thicker and will absorb more total liquid.

But, there are other factors that determine the quality of a towel.

The main factor is the quality of the yarn. Secondary factors are the construction of the towel. The machines that the material is woven on. The precision of the fiber “splitting” process.

Lower quality microfiber material can be made to have a higher GSM and use less microfiber material, by utilizing a thicker “base layer” of 100% polyester.

Most microfiber material is made by weaving the surface yarn through a base layer. The surface yarn is the part of the material with pile, on the outside, that you feel. The base layer is the structure that the surface layer yarn is woven through.

It is possible to make less expensive and lower quality towels that feel heavier and weigh (higher GSM) more by using a thicker base layer yarn. For example, there are some towels in which the base layer is up to 50% of the total fabric weight.

How does it change cleaning ability?

All else being equal, higher GSM material, will have more microfiber and will be thicker and absorb more water.

Many higher GSM Towels will have a higher pile which can reduce surface pressure when wiping. Lower GSM towel will often have a lower pile and will be more aggressive when scrubbing.

Other factors, like the weave type, construction, and yarn quality will have more effect on cleaning ability than GSM.