GSM Explained for Bulk Joggers
By The Velocity Wear Team
GSM means grams per square metre: the weight of the cloth, measured over a fixed area. On joggers it tells you how substantial the fabric is and roughly what it will cost, but it says nothing about softness, stretch or how long the garment lasts. A brushed fleece and a loopback at the same GSM feel completely different in the hand, which is why the number alone never decides an order.
What is the number actually measuring?
Cut a square metre of the knit, weigh it, and that is the GSM. Nothing else is included. Two fabrics at the same weight can be built from different yarns, knitted at different densities and finished differently, and the buyer will notice all of that before noticing the weight. Treat it the way you would treat the thickness of paper: useful, comparable, and not the whole specification. The same principle across other garments is set out in GSM explained for buyers.
Why does brushing change how a weight feels?
Brushing pulls the loops on the inside of the knit into a nap. That traps air, so a brushed fleece feels warmer and bulkier than a loopback of identical weight, and it also gives the surface something for lint and pilling to work on. Loopback keeps those loops intact: flatter, cooler, quicker to dry and steadier through repeated washing. If you want warmth, ask about brushing. If you want durability through a laundry cycle, ask about construction. The weight is the third question, not the first.
Does a higher number cost more?
Generally, because there is more yarn in the garment, but quantity moves the price far more than weight does. The published from-price on our wholesale joggers page is $22 a piece at the fifty-piece minimum, and the tiers step at 50-99, 100-249, 250-499, 500-999 and 1,000-plus, taking up to 35% off that fifty-piece price. Moving up a tier will save you more than dropping a fabric weight, and it does not cost you a worse garment.
How does weight interact with decoration?
Heavier, denser cloth gives embroidery and 3D puff a stable base, so the stitch sits cleanly without the fabric distorting. Lighter and softer cloth needs more backing to achieve the same thing. Screen printing prefers a flat surface, so a napped fleece can blur fine detail regardless of its weight. If your artwork has small type or thin lines, bring it up when the fabric is being chosen rather than at proof stage.
How do you check the weight without seeing the cloth?
Ask for it in writing on the quote, alongside the construction and whether it is brushed, and use the shared vocabulary in our glossary so both sides mean the same thing. Then order a sample. At £150, credited against the bulk order, it turns a number into a garment you can hold, and it is the only reliable way to settle a fabric argument. The practical trade-off between weights is worked through in midweight vs heavyweight on joggers.
Be careful comparing weights between suppliers. One quote may describe the finished, brushed cloth and another the fabric before finishing, and those are not the same figure even when they carry the same label. Ask which is being quoted, and ask whether the construction is loopback or fleece in the same sentence. Two numbers without that context tell you nothing useful, and a buyer who picks the higher of the two can easily end up with the thinner-feeling garment of the pair.
