What is GSM Test Method & Factors that Affect The Accuracy of GSM Test


The consistent quality of products is vital for the manufacturing industry. Many big brands that endured over a century have strict quality inspection procedures.

They usually work with an impartial third-party quality control team. The professionals will conduct product quality inspections and monitor the production process. After this, only the excellent quality products are shipped off to the suppliers or the customers.

In most cases, the QC inspectors use GSM test methods to ensure excellent quality. We’ll share everything about the GSM test that industries usually perform. Let’s get started.

What is a GSM Test?

GSM refers to “gram per square meter” and is expressed in g/m². It is a standard unit for measuring the weight of the items such as paper, cardboard, fabrics, etc. Usually, a company will have a GSM target depending on the product usage and the required cost.

To meet the manufacturing requirements, a one-meter by one-meter sheet of materials will be cut. It will then be weighed in grams to compare the material quality.

For example, in the textile industry, textiles of 1m² are acquired using a GSM cutter. Then, the quality inspection team will weigh it using a weighing balance.

The total weight is then averaged to obtain the official GSM number. The standard tolerance of the GSM test is about +/- 3%. Hence, a 300 g/m² material can differ between 291 and 309 g/m².

Importance of the GSM Test

The GSM test is a quality calculating method important in many industries. This method guarantees the product safety and makes sure it is free from any defect.

You should choose the product packaging wisely to deliver an item with no flaws. Some commonly used materials for packaging are paper, cardboard, corrugated boxes, and fabrics. It is also vital to ensure that the products are unbroken throughout the delivery process.

If a company is not paying attention to product quality, it can bring harmful consequences. The product might damage when exposed to actual working circumstances. It may lead to a fatal accident which affects the brand image and reputation.

The Common Products that Perform GSM Test

fabric weight check and gsm test1.   Textiles

You can use textile materials in many applications. For instance, clothing, curtains, cloth, parachutes, tents, etc. Textiles like tents and parachutes require inspection under specific conditions. Otherwise, degraded textiles used may cause unwanted accidents.

In this case, the GSM test helps signifies the textiles’ strength, endurance, and quality. It also tells about the time to perform the fabric processes.

2.   Paper

Paper in the market comes in different sizes, thicknesses, and strengths. The common uses of the paper include schools, offices, printing, and packaging industries.

Many manufacturers use the GSM result to decide the quality of the paper. From there, they can better determine the paper’s pricing.

3.   Cardboard

Cardboard is made of recycled paper or recycled cardboard. It is one of the major components in many industries. For instance, schools, packaging industries, and so forth.

The flute of the cardboard is sandwiched in two different liners. The cardboard may degrade over time as it is made of recycled materials.

Thus, the GSM test is vital to keep track of the cardboard quality. It helps ensure the safety of packaging products.

4.   Corrugated Sheets

Corrugated sheets could efficiently bear the weight acting on them during delivery. So, it is the most famous option for packaging boxes.

To make corrugated boxes, a layer of corrugated sheets is placed on one or more sheets. They will be glued with the assistance of a strong adhesive.

With the GSM test, you can define the strength of the corrugated sheets. It is calculated by specifying the bursting index and bursting factor. You can then ensure that the correct strength corrugated box is used for the right application.

GSM Test Instruments for Product Inspection

GSM Cutter for GSM Test
GSM Cutter

1.    GSM Cutter

A GSM cutter is a circular fabric sample cutter used for measuring fabric GSM. It is usually used to cut a uniform circular fabric of a 100 cm2 area without measuring. The instrument is equipped with four replaceable edges and ordinary cutting pads.

2.    Weighing balance

A weighing balance is used to measure basis weight. Some of the weighing balances are specially designed to use the GSM test. These balances have a plastic cover to prevent errors while weighing the material pieces.

3.    GSM Pad

A GSM pad is a cutter pad used along with the GSM cutter. It is placed below the cutter and the materials to provide a smooth surface. You can perfectly cut the materials with a GSM pad and a GSM cutter.

Ways to Perform GSM Test

Weight the fabric in gsm test1.    Testing Instrument (GSM Cutter and Weighing Balance)

In this method, a piece of material is brought to the surface of the GSM pad. Next, the creases of the material (textile) are removed. The material will be cut with the GSM cutter to form a circular sample piece. The sample is then weighed with the weighing balance. Lastly, the GSM of the piece is determined with the GSM formula below:

Grams per square meter = (Weight of sample in grams x 1000) / area of the sample in cm²

2.    Formula

This GSM test method is only applicable for the GSM test of woven fabric. You can use this formula in the absence of testing instruments. Make sure you have the textiles’ information below to use this formula.

  • Fabric yarn count – warp count and weft yarn count
  • Warp and weft density – End per inch (EPI) and picks per inch (PPI)
  • Percentage of warp and weft crimp

This GSM test method is less recommended as the data of the fabric are not easy to get. Information like EPI, PPI, and crimp percentage requires a longer time to process. Also, there is an issue of precision level when measuring texture GSM from texture development and utilizing this formula.

Fabric GSM calculation formula:

Fabric GSM = (EPI/warp count + PPI/Weft count) x (100+crimp %) X 0.2327

Factors that Affect The Accuracy of GSM Test

1.   Moisture and Atmospheric Humidity

Moisture and humid atmospheric conditions would affect the accuracy of the GSM test. It will cause an increase in the weight of the samples, resulting in a false GSM test result.


You should ensure dry atmospheric conditions when performing a GSM test. It could help prevent the samples from absorbing the moisture in the air. Some weighing balances have a plastic cover to avoid the surrounding dampness and increase test precision.

2.   Unbalanced Scale

There might be a mistake on the scale of the sample piece. Human errors made it difficult to obtain a perfect scale while cutting the material pieces.


You should check the scale reliability before running the GSM test. If there is an unbalanced scale, the GSM test needs to be completed again to ensure accuracy.


Many manufacturers use a GSM test to define the quality and strength of their products. You can easily run the GSM test using a GSM cutter, weighing balance, and the GSM pad.

It is important to note that not all high GSM test results products are of good quality. Taking towels as an example, it is not just the GSM of the towel that makes it expensive, but the yarn quality. So, make sure you understand your product well before conducting a GSM test.

I hope this article helps you gain more information about the GSM test and ways to conduct it. Feel free to contact us for more details regarding the GSM test.


Author: AQI Service as a professional quality control service company in China specialized in providing a complete range of quality inspection and testing certification services in China & Asia for global importers, buyers, retailers, and sellers.