"320 gsm cotton fleece" describes weight and nothing else. It says nothing about yarn count, loop structure, shrinkage, spirality, pilling or hand feel – all of which decide whether a garment survives a retail wash test.
What a real fabric spec contains
- Composition with tolerance, e.g. 80% cotton / 20% recycled polyester ±3%.
- Construction: knit type, gauge, yarn count and whether the face is brushed.
- Finished GSM and the acceptable range, measured after finishing not greige.
- Dimensional stability: shrinkage after three domestic washes at 40°C.
- Colour fastness to washing, rubbing and light, with the test method named.
- Pilling grade and any anti-pilling or enzyme finish applied.
Why this matters for bulk
A mill can hit 320 gsm with a cheaper open-end yarn and a heavier brush. The sample looks right, the hand feel is close, and then the first wash twists the side seam by four centimetres. Re-cutting a 3,000-piece order is far more expensive than specifying the yarn at the start.
If the fabric spec has only one number on it, that number will be right and the garment will still be wrong.
For every program we issue a fabric sheet with the mill name, construction, test reports and approved lab-dip references. It becomes part of the sealed sample, so a repeat order six months later has something objective to be checked against.