How to Choose the Right GSM for Your Nonwoven Application

GSM stands for grams per square meter. It is a measure of fabric weight, or basis weight. A 60 gsm fabric weighs 60 grams for every square meter of material. GSM is the most fundamental specification in nonwoven fabric because it directly correlates with thickness, strength, absorbency, and cost.

In the nonwovens industry, GSM is sometimes written as g/m2 or gpy (grams per square yard in US units). The international standard is ISO 9073-1, which specifies the method for measuring basis weight.

Lower GSM means lighter, thinner, and cheaper fabric. Higher GSM means heavier, thicker, and more expensive fabric. But the relationship between GSM and performance is not always linear, which is where many specification mistakes happen.

Understanding how GSM influences each property helps you make trade-off decisions. Here is a breakdown:

Different applications have established GSM ranges based on performance requirements and cost targets. Here are the ranges we see most frequently at SunLuner:

In our experience working with buyers across industries, these are the most frequent mistakes we see in GSM specification:

GSM, material blend, and fabric strength form a triangle. You can increase strength by: (a) increasing GSM, (b) adding polyester, or (c) both. The most cost-effective approach is usually to add polyester and keep GSM lower, rather than using pure viscose at high GSM.

For example, if you need a wiping fabric that does not tear when wet, a 50 gsm 70/30 viscose/polyester on our direct-laid line will typically cost 20-30% less than a 70 gsm 100% viscose at similar wet strength.

Embossing patterns affect effective thickness and hand-feel. A 60 gsm plain fabric feels different from a 60 gsm large pearl fabric, even though they weigh the same. If you are matching an existing product, specify both GSM and pattern, not just GSM.

Fabric cost is roughly proportional to GSM because more fiber is used. However, the cost curve is not perfectly linear due to processing constraints:

At very low GSM (below 35 gsm), the web becomes difficult to form uniformly, and production speed may need to decrease, which increases cost per kilogram. At very high GSM (above 100 gsm), drying time increases, which also affects throughput.

The most cost-efficient GSM range for spunlace is typically 50-80 gsm, where production lines run at optimal speed and fabric uniformity is easiest to maintain.

GSM is measured using ISO 9073-1. The standard method involves cutting a known area of fabric (typically 100 cm2 or larger) and weighing it on a precision balance. The result is expressed in g/m2.

At SunLuner, we test GSM every 50 meters during production using inline scanning and verify with laboratory gravimetric testing. Our GSM tolerance is plus or minus 5%, which is industry standard for spunlace.

When you receive samples, always verify GSM yourself using a circular cutter and balance. A discrepancy of more than 5% from specification is grounds for rejection.

Our 5 production lines cover different GSM ranges. Here is what each line can produce:

Use this decision framework to narrow down your GSM specification: