Two rolls of knitted fabric can carry the same composition and behave differently, because the figure that matters is not the nominal value but where the process sits inside the tolerance.
What composition actually controls in knitted fabric
Drives shrinkage, pilling and price more than any machine setting.
That makes it a design decision rather than a purchasing one, which is why changing it after the product is fixed costs more than changing the material.
For Knitted fabric, the working range is 100 % cotton / CVC / TC / 100 % polyester. Inside that band the choice is commercial; outside it, the product changes category and so does the price.
How to choose a composition option
| Option | What it changes in knitted fabric | When it is the right choice |
|---|---|---|
| 100 % cotton | The lowest-cost option in the family. Shrinkage beyond claim is where it usually ends up. | Cost-led programmes with a short service life |
| TC | The volume middle: enough margin for process variation without paying for headroom the end product cannot use. | Most repeat programmes, and the safest default |
| 100 % polyester | The top of the family, where the process is controlled tightly enough to guarantee it. | A warranty, a tender, or a specification that cannot be renegotiated |
These are alternatives, not points on a scale. Composition is chosen by the application rather than by price, and a supplier who quotes one option as if it were interchangeable with another is quoting a different product.
The middle is where most programmes should sit, and it is the hardest position to defend in a price meeting because it has no story attached to it.
The figure that decides the outcome is not composition itself but the tolerance around it. A supplier who quotes 100 % cotton / CVC / TC / 100 % polyester without a tolerance has not quoted a specification, and the first lot will define the tolerance for you.
How to measure composition
The reference method here is Skew, run to AATCC 179, with an acceptance of <= 5 %. The method is the easy part; sampling and conditioning are where reports diverge.
Ask which instrument was used. For composition, two instruments that both claim the same standard can differ by enough to move a marginal lot from pass to fail.
Record the measured value rather than pass or fail. A marginal pass on composition tells you the process is running at the edge, which is the information you need before the next lot rather than after it.
Composition does not stand alone
Composition moves with weight (120-320 gsm) and with stitch length (2.6-3.4 mm). Tightening one usually costs money in another, and a supplier who accepts every tolerance without comment has either not understood the interaction or is planning to substitute.
This is why a specification written as a list of independent tolerances is weaker than one written as a construction. The list lets a supplier satisfy each line while missing the product.
The clause to write for composition
The line below is the version we can quote against without inventing anything. Composition appears with a tolerance and a test, not as a standalone number.
Single jersey, 100 % combed cotton, 180 gsm +/- 5 %, open width 175 cm, stitch length 2.9 mm, shrinkage <= 5 % after 3 washes, skew <= 5 %, reactive dyed, Pantone 19-1664 TCX
A specification without a test method is a preference. It becomes a requirement when the method and the acceptance value are both named, because then a substitution is visible.
When composition goes wrong
Shrinkage beyond claim. Garment drops a size in the first wash.
The cause is usually insufficient compaction, or a compactor setting changed between lots.
The test that catches it: ISO 6330 domestic wash at 40 C, then ISO 5077 dimensional change, 3 cycles.
What to specify instead: Specify 3-cycle figures, not 1-cycle, and hold the compactor setting as a controlled parameter.
None of this is visible in a quotation. It becomes visible in a retained sample and a lot record, which is why the paperwork matters more than the price on this parameter.
Four questions about composition, before you order
- What tolerance do you hold on composition, and what did your last three lots measure against it?
- Which method do you use for skew, and which laboratory signs the report?
- When composition falls outside 100 % cotton / CVC / TC / 100 % polyester, do you rework, downgrade, or ship and hope?
- Which of weight or stitch length would you move first to hit a lower price?
The answers are more useful than a certificate, because they show whether the process is controlled or merely inspected. Full ranges for knitted fabric are on the product page, and the measurement regime is described on the quality control page.
Questions buyers ask before ordering
Do you offer compacted fabric?
Yes, and we recommend it for any garment that will be washed by the end consumer. Compaction adds cost and removes most shrinkage claims.
What is your minimum for a custom colour?
500-800 kg depending on shade depth. Stock white and black can go lower.
Questions worth asking before the price is agreed
The questions below are the ones that cannot be answered from a catalogue, which is exactly why they are worth asking.
| Question | Answer that should worry you | Answer that holds up |
|---|---|---|
| Who signs the test report, and against which standard? | “Our QC department signs it.” | A named standard, a named method and a signature that belongs to somebody who can be asked again next year. |
| How do you hold skew (torque) at <= 5 %? | “That is standard for us, no problem.” | The last three lots’ readings, the instrument used and who signs the report. Pilling starts here. |
| What happens if composition misses the 100 % cotton / CVC / TC / 100 % polyester requirement? | “It will not happen.” | A re-test clause, the tolerance on the re-test, and the point at which the lot is remade rather than discounted. |
Failure modes worth a clause in the purchase order
Claims rarely come from a batch that was obviously wrong. They come from a structure figure that sat inside the quoted band and outside what the product needed.
| Failure | What triggers it | Test to demand on the production lot |
|---|---|---|
| Shrinkage beyond claim | Insufficient compaction, or a compactor setting changed between lots. | Dimensional change — ISO 6330 + ISO 5077; acceptance <= 5 % after 3 washes |
| Barre (fabric bars) | Yarn count variation or uneven tension across the beam. | Skew — AATCC 179; acceptance <= 5 % |
The other two, with acceptance numbers attached, are in the full failure analysis for knitted fabric. A supplier who cannot name the mode he sees most often is describing a catalogue, not a process.
Need composition specified and tested against your end use?
Send the end use, the quantity and the destination market, and we will come back with a specification that meets it, a price at your volume and the test reports that back it up. Samples are free for qualified programmes; we charge the courier only.
Related reading
Sample cut with your values on it · Neutral packing and private label · Consolidation, documents and lead times
