How to Check Fabric Quality Before Buying: GSM, Shrinkage, Colourfastness and Pilling

The six checks, and how to run each one

Weight, in GSM, is the cheapest comparison and the most useful. GSM is grams per square metre, and two fabrics at the same price can differ wildly in weight. If a supplier quotes a 180gsm cotton jersey, you can weigh a sample on a small scale or ask for the weight from the mill’s specification. Weight drives how the garment hangs, how warm it is, and how it wears, and it is one of the few things that can be checked without destroying the sample.

Fibre composition is a documentation check, not a physical one. Every textile sold into most markets must carry a correct fibre content label, and the label must match the cloth. Ask for the composition in writing — cotton, cotton-polyester ratio, viscose, modal, elastane percentage — and compare it against the mill specification and against the label on the garment you have been shown. A mismatch between the mill spec and the finished label is a serious finding, and it is a compliance problem in your market as well as a quality one.

Shrinkage is where visual inspection fails. Take or buy a sample, measure it marked and unmarked, wash it the way the care label says a customer will, dry it as the customer would, and measure again. The industry norm for a quality knit is around 3 to 5 percent; much beyond that and you have a returns problem you did not see coming. This single test catches more trouble than any other, because a fabric that shrinks badly is a fabric that fails in the customer’s hands and comes back to you.

Colourfastness is checked by rubbing and by washing: a white cloth rubbed against the fabric should show little or no colour transfer, and the wash test should leave the colour in the cloth rather than in the water. Poor crocking is invisible on day one and appears as the first wear on a dark garment.

Pilling and abrasion are tested by rubbing a fabric against itself repeatedly and seeing whether a ball forms. This matters enormously for polyester blends and for anything soft and loosely woven — and it is the difference between a garment that looks new after a month and one that looks tired.

Stitch and seam strength is checked by pulling: seams should not open under hand tension, and the thread should not cut into the fabric. Weak seams fail in wear rather than in the warehouse, and they are a manufacturing quality signal that predicts a lot of other things about the lot’s production.

Ask for these in writing before you pay

A serious supplier answers a quality question with a specification and a test method, not an adjective. So ask, in writing: the GSM, the fibre composition and percentage, the shrinkage figure and how it was tested, the colourfastness rating and against what standard, and the pilling rating. If the answer is “good quality” or “fine cloth”, that is itself information about the supplier.

Ask for a physical sample, in quantity, before you commit to bulk. The sample you approve becomes the standard the bulk is judged against, so agree that explicitly: “this sample is the reference for the delivery.’ That sentence is the beginning of most disputes being avoided. Photograph and weigh the reference sample, and keep it.

Then use an inspection before stuffing, which is the only point where finding a problem is still cheap. A third-party inspection at the factory catches lot composition, count and condition problems before the container is sealed. Once it is loaded, the leverage is gone — which is why the inspection, the sampling and the agreement on what the sample represents all happen before loading, not after.

What each failure costs downstream

Understanding the cost makes the checks easier to insist on. Excessive shrinkage becomes returns, and in most markets returns eat more margin than the discount ever won you. A fibre composition mismatch becomes a compliance problem, a relabelling cost and potentially a withdrawal. Poor colourfastness becomes complaints on the exact product you built a promotion around. Pilling makes a good garment look worn within weeks and destroys repeat sales in a category where repeat sales are the whole business.

None of these are dramatic at the sample stage, and all of them are dramatic at 20,000 pieces. That asymmetry is the argument: the checks cost hours and a little soap; skipping them costs a container.

The practical routine that works is a standing one. Every new supplier gets a sample and the six checks. Every bulk order is compared to the approved reference sample by weight and by specification. Every bulk order gets an inspection before stuffing. And every specification lives in a file with the reference sample in it, because the standard is what you defend later.