Why GSM Alone is a Flawed Indicator in Technical Textiles

In the world of technical textiles, “GSM” is often treated as the universal shorthand for quality.

It appears in every datasheet, quotation, and purchase order—yet it is one of the most misinterpreted and incomplete performance indicators in our industry.

At Macfil Global Pvt Ltd, we have seen too many procurement, QC, and design decisions fail because GSM was treated as the deciding metric. This article explains why GSM alone cannot determine a fabric’s suitability—and what seasoned professionals should be measuring instead.

1. GSM Measures Weight, Not Performance

GSM (grams per square metre) is simply the fabric’s weight over a given area.

It tells you nothing about:

• Fibre composition and polymer characteristics (e.g., high-tenacity polypropylene vs. commodity PP).

• Yarn structure (multifilament, monofilament, fibrillated tape, spun yarn).

• Weave or knit construction, which directly impacts tensile strength, filtration properties, and dimensional stability.

• Surface finishes or coatings, which influence UV resistance, chemical durability, or abrasion tolerance.

Two fabrics with identical GSM can deliver entirely different field performance.

2. Density and Weave Structure Matter More

In woven fabrics, ends per inch (EPI), picks per inch (PPI), and yarn crimp directly control mechanical behaviour.

Example:

• A 220 GSM tape x multifilament woven geotextile with high warp density can outperform a 300 GSM loose weave in puncture resistance and filtration stability.

• High yarn modulus and compact structure can deliver superior tensile performance even at lower GSM.

The assumption “heavier equals stronger” is a frequent—and costly—misjudgment.

3. GSM Cannot Predict Functional Properties

Each technical textile application has primary functional drivers that are not weight-dependent:

Lighter but structurally engineered fabrics often outperform heavier alternatives in these metrics.

4. GSM is Easily Manipulated

GSM can be artificially increased—without any actual performance improvement—by:

• Using thicker, low-tenacity yarns.

• Over-applying coatings that add weight but reduce flexibility.

• Introducing fillers or moisture during production.

A fabric can “pass” GSM requirements on paper, yet fail in application-specific tests.

5. The Scientific Reason GSM Fails as a Standalone Metric

From a materials science perspective, mass alone is never a reliable predictor of mechanical performance. Polymer crystallinity, molecular orientation, yarn interlacing, and load path distribution play a far greater role.

Global standards (ASTM, ISO, BIS) always pair GSM with multiple structural and performance parameters for this reason—weight is a supporting figure, not a deciding factor.

Macfil Global’s Approach

At Macfil Global Pvt Ltd, GSM is only the starting point of our engineering process.

Every woven geotextile, FIBC fabric, or agro-textile we produce is validated through application-specific test parameters—from tensile modulus to UV retention—ensuring real-world performance, not just numbers on a datasheet.

For mission-critical projects, we advise procurement and QC teams to demand full technical data sets, not single-number specifications.