Microfiber Towels and GSM: What you Need to Know

By Ian Rammelkamp, President of Autofiber

A version of this blog post originally appeared on Autofiber's website. The original post can be seen here: https://www.autofiber.com/blogs/microfiber-university/what-is-gsm

What is GSM?

GSM is a benchmark specification to meet production quality requirements and compare different microfiber materials. GSM stands for Grams per Square Meter (g/m2).

​​When we at Autofiber design a new product, we have a GSM target and tolerance depending on the product's use, the weave, and the required cost. We then determine that we are meeting that target GSM tolerance during the production process, and that the target GSM tolerance is met before it is shipped to our customers and distributors.

That means that every microfiber product you purchase from Autofiber (and at Car Supplies Warehouse) will be within 3% of the stated GSM.

Is higher GSM Better?

When we isolate GSM as a method to rate a microfiber product's performance, we find that the higher the GSM, the thicker and more absorbent the microfiber is. However, there are other factors that determine the quality of a microfiber towel.

For example, some low quality microfiber materials can produce high GSM readings, but only because they utilize a thicker "base layer" of 100% polyester, changing the towel's microfiber content and producing a less absorbent product overall.

When asking questions about the quality of a microfiber material, we need to be concerned with its manufacturing process, especially in regards to its surface yarn. Most microfiber material is made by weaving surface yarn through a base layer. The surface yarn is arranged to make the pile that you see and feel on the surface of the towel.

​​It is possible to make less expensive and lower quality towels that feel heavier and weigh more (higher GSM) by using a thicker base layer yarn.

What does GSM mean for a towel's cleaning ability?

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

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

This means that generally speaking, lower GSM towels (500 and below) should be your go-to tool for interior detailing, coating leveling, and polish removal. Higher GSM towels (above 500) are generally best for drying a vehicle. There are some notable exceptions to this general rule though: waffle weave towels usually have a GSM between 350-400, but due to their weave, are usually able to hold almost 10 times their weight in water.

How can I tell determine a towel's GSM?

To determine the GSM of your towel you will need a scale capable of measuring in grams, and a tape measure.

First, weigh the towel in grams and measure the towel's length and width in centimeters. (NOTE: to convert centimeters to inches, divide the distance by 2.54)

Second, convert centimeters to meters by dividing each length and width by 100.

Then, multiply the length and width to find the total area of the towel in square meters.

Finally, divide the grams by the square meters.

Example 1:

Towel weight: 50 grams

Towel size: 16” x 16”: 40.64 x 40.64cm

  • ​​0.4064 x 0.4064
  • ​0.165
  • 50 / 0.165 = 303 GSM

​​Example 2:

​​Towel weight: 200 grams

​​Towel size: 16” x 24” : 40.64 x 60.96

  • ​​0.4064 x 0.6096
  • 0.2477
  • 200 / 0.2477 = 807 GSM

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