Moisture-Wicking Fabric Explained: What GSM Means for Your Jersey

GSM stands for grams per square metre. It is the weight of one square metre of a fabric, and it is the single most useful number on a jersey specification. GSM predicts opacity, durability, drape and heat retention. It does not by itself predict wicking, which is a separate property built from fibre chemistry and knit structure. This guide explains both, gives weight ranges by sport, and shows what changes when you move a jersey 20 GSM in either direction.

What GSM Measures

A 150 GSM jersey fabric weighs 150 grams per square metre. A typical adult jersey uses roughly 0.7 to 0.9 square metres of cloth, so the fabric in that garment weighs around 105 to 135 grams. Two fabrics at the same GSM can still feel different, because weight says nothing about how the yarn is knitted or how thick each filament is. GSM sets the envelope, and knit structure fills it.

How Moisture-Wicking Actually Works

Polyester is hydrophobic, meaning the fibre itself does not absorb water. That is the starting point, not the mechanism. Wicking happens because the yarn is engineered with capillary channels that draw liquid along the fibre surface and spread it across a wide area, where it evaporates faster. Three factors control performance.

• Filament shape. Grooved or multi-global filaments create more capillary channels than round ones.
• Knit structure. An open knit moves air; a dense knit slows evaporation regardless of yarn quality.
• Finish. A hydrophilic finish on the inner face pulls moisture off skin and hands it to the outer face.

Cotton does the opposite. It absorbs up to 25 times its weight in water, holds it, and gets heavier as a match progresses. That is why no serious team jersey uses cotton, and why sublimated polyester dominates the category. Fibre and construction characteristics for each base cloth are listed on our fabric types page.

Knit Types and What They Do

Strong jerseys mix knits. A common build uses interlock across the chest for print quality and micro mesh at the sides and upper back for airflow, which delivers opacity where the graphics are and ventilation where sweat concentrates.

GSM by Sport

Compare finished specifications across our product categories, including the fitted cuts in our volleyball jerseys range and the reinforced construction in our football jerseys category.

What Changes When You Move 20 GSM

The practical rule is simple. Season length and contact level set the floor, and playing temperature sets the ceiling. A youth team playing 12 indoor games should not buy 190 GSM, and a travel baseball programme playing 60 games should not buy 140 GSM.

Climate and Venue Matrix

Reading a Fabric Specification

A complete jersey fabric specification carries five numbers, not one. Suppliers that quote only GSM are giving you a fifth of the picture.

Ask for all five in writing when comparing quotes. Two jerseys quoted at 155 GSM can differ by a full season of usable life once composition and filament type are known.

Care Rules That Protect Wicking

• Never use fabric softener. It deposits a coating that blocks capillary channels and permanently reduces wicking.
• Wash cold or warm, not hot. Repeated high heat degrades elastane and shortens recovery.
• Skip the dryer where possible. Hang drying takes minutes longer and adds seasons of life.
• Avoid chlorine bleach. It weakens polyester and attacks any stitched decoration.
• Wash inside out on any garment carrying surface decoration.

Sublimated graphics tolerate this regime better than any surface print, because the ink sits inside the fibre rather than on top of it. That difference is set out in our comparison of stitched vs sublimation, and method mechanics are covered on our printing methods page.

Cost Consequence of Getting GSM Wrong

Under-specifying is the expensive mistake. Over-specifying costs a modest premium and buys comfort problems in summer play rather than budget problems.

Questions Teams Ask About Fabric Weight

Is higher GSM always better quality?

No. Above roughly 185 GSM a game jersey becomes hot without becoming more durable in any way that matters indoors. Weight is a specification, not a quality grade.

Why does my light jersey show sweat?

Opacity falls with weight. Below about 140 GSM in a pale colour, saturation becomes visible. Move up 15 to 20 GSM or place a mid-tone panel across the torso.

Do jerseys stop wicking over time?

They do when fabric softener has been used, or after the finish degrades through repeated hot washing. Correct laundering preserves performance for the life of the garment.

How do I check a supplier’s actual GSM?

Ask for it in writing before ordering, and order a single sample garment to confirm. Measured sizing sits on our size chart, and specification questions can be raised directly.

Specifying Weight With Confidence

Set GSM from season length and contact level first, then check it against playing temperature, then choose a knit that puts opacity where the graphics are and airflow where the sweat is. Most teams land correctly between 145 and 165 GSM. Browse finished specifications in our shop or read further specification guides on our blog, then tell us your sport, season length and venue through the contact page and we will recommend a weight and knit combination with the reasoning attached.