Two suppliers can quote the same cotton and t/c fabric at the same headline figure and deliver different products. The difference is in the numbers nobody puts in the quotation, and in the tolerance behind the number that is quoted.
Why the headline number is the least useful one
Every quotation leads with composition. It is easy to compare and it is the number the factory can hit most cheaply. But it tells you almost nothing on its own: composition sets the frame, and the parameters below set whether the product survives its first year in service. A buyer who compares only the headline figure is buying a sample, not a supply agreement.
For cotton/T.C, the practical rule is to fix the headline figure at the level your product needs and then spend your negotiating attention on construction and density. Those two are where cheap goods differ from adequate goods, and they are usually absent from the quotation sheet.
The numbers that decide performance
| Parameter | Typical range | What it changes |
|---|---|---|
| Composition | 100 % cotton / 65-35 / 80-20 T/C | Shrinkage, hand, price and the care label all follow from this. |
| Yarn count | 16s / 20s / 21s / 32s / 40s | Finer yarn is smoother and weaker; 20s-21s is the workwear sweet spot. |
| Construction | 1/1 plain / 2/1 twill / ripstop | Twill drapes and hides stains; plain is cheapest and shows everything. |
| Density | 88×56 to 133×72 threads/inch | The real weight and durability driver, and the number suppliers omit. |
| Weight | 100-250 gsm | Workwear needs >= 180 gsm for a two-year life claim. |
| Shrinkage | <= 3 % pre-shrunk, <= 6 % raw | The number that decides whether the garment fits after the first wash. |
| Colour fastness to washing | >= grade 4 | Dark shades in workwear fail here first. |
| Finish | mercerised / sanforised / easy-care / FR | Each finish adds cost and changes the hand; easy-care reduces strength. |
Read the table as a set of trade-offs rather than a checklist. Moving any single line usually costs money somewhere else, and the cheapest way to hit one figure is often to let another slip.
Composition
Typical range: 100 % cotton / 65-35 / 80-20 T/C. Shrinkage, hand, price and the care label all follow from this.
Yarn count
Typical range: 16s / 20s / 21s / 32s / 40s. Finer yarn is smoother and weaker; 20s-21s is the workwear sweet spot.
Construction
Typical range: 1/1 plain / 2/1 twill / ripstop. Twill drapes and hides stains; plain is cheapest and shows everything.
Density
Typical range: 88×56 to 133×72 threads/inch. The real weight and durability driver, and the number suppliers omit.
Weight
Typical range: 100-250 gsm. Workwear needs >= 180 gsm for a two-year life claim.
How to write a cotton/T.C specification that protects you
A specification is only useful if a substitution becomes visible. That means writing the construction and the performance together, and naming the test that proves each one. For cotton/T.C, the clause has to pin construction and density, because those two separate a compliant lot from an adequate one:
65/35 polyester/cotton twill, 21s x 21s, 108×58, 240 gsm, 160 cm, sanforised shrinkage <= 3 % after 3 industrial washes, colour fastness to washing >= grade 4, Pantone 19-4127 TCX
Note what is missing from that line: adjectives. No ‘high quality’, no ‘premium’, no ‘export grade’. Every clause is either a number with a tolerance or a named test. If a supplier cannot quote against a line written this way, that is information about the supplier.
Where the specification usually breaks down
The first failure is shrinkage. Uniforms shrink a size after the first industrial wash. The cause is usually no sanforising, or sanforising settings not held between lots. The test that exposes it before you order: ISO 6330 at 60 C industrial cycle, 3 washes, then ISO 5077.
The second is shade variation between lots. Trousers from two deliveries do not match under shop lighting. It comes from dye lot change and metamerism, worst with t/c blends. Test with D65 and TL84 visual plus dE <= 1.0 spectrophotometer. and write the result into the purchase order, not just the enquiry.
Both failures share a pattern: they appear months after delivery, they are hard to attribute, and the cost lands on the buyer rather than the mill. That is exactly why the test belongs in the specification and the report belongs in the shipment file.
What to put in a cotton/T.C enquiry
- End use and the conditions, which together decide where construction has to sit inside 1/1 plain / 2/1 twill / ripstop.
- The one figure that must hold, with shrinkage named as the proof.
- Quantity per colour and per delivery, against a typical MOQ of 1000-2000 m per colour.
- Destination market, because compliance changes the construction, not just the paperwork.
- A physical standard viewed under a stated light source, not a screen proof.
With those five points we can quote against a real requirement instead of a generic range. Full ranges sit on the cotton/T.C page, and the manufacturing side of the same question is on our quality control page.
Questions buyers ask before ordering
Do you supply 3-cycle shrinkage figures?
Yes, and we recommend insisting on them. A 1-cycle figure hides progressive shrinkage, which is what ruins uniforms.
Can you match a shade in both 100 % cotton and T/C?
We can, but the reflectance curves differ and metamerism is real. Approve the swatch under both D65 and TL84.
What is the minimum for a custom shade?
1000-2000 m depending on depth. White and black can go lower.
Failure modes worth a clause in the purchase order
Claims rarely come from a batch that was obviously wrong. They come from a colour fastness to washing 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 | No sanforising, or sanforising settings not held between lots. | Tensile strength — ASTM D5034; acceptance >= 350 N |
| Shade variation between lots | Dye lot change and metamerism, worst with T/C blends. | Colour fastness to washing — ISO 105-C06; acceptance >= grade 4 |
The other two, with acceptance numbers attached, are in the full failure analysis for cotton/T.C. A supplier who cannot name the mode he sees most often is describing a catalogue, not a process.
Seven lines that turn a quotation into a specification
Most post-delivery arguments are not about quality. They are about a document that never said which figure would be measured, on which instrument, at whose cost.
- Finish (mercerised / sanforised / easy-care / FR): fix the value per shipment, and state who pays for the re-test if a lot lands outside it.
- Composition: 100 % cotton / 65-35 / 80-20 T/C is not an answer on its own. Ask for the last three lots’ actual readings and the spread behind them.
- Yarn count: agree the test method with the number. Two labs, two methods, two answers, one argument.
- Construction (1/1 plain / 2/1 twill / ripstop): state where in the band this order sits. The middle of the band is not what a tolerance is for.
- Price validity: the period during which the quoted figure holds, and what happens to it when the raw-material index moves.
- Remedy: rework, replacement or credit, and the point at which each applies.
- Sample retention: one production sample per lot stays with the mill for twelve months. Claims are settled against it, not against memory.
Need this specified 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
