Locate the named components
For the selected Black Mix two-pack, M&S lists 85% cotton and 15% polyester exclusive of trimmings, plus 100% cotton pocket lining. The latter refers to the lining, not a second description of the whole pair. The public record does not provide the mass of either component.
Do not infer a total blend
An overall percentage cannot be calculated from those figures without component weights. The two-pack count also supplies no information about the amount of lining or cotton in each pair. Its £8 derived per-pair price is a purchase calculation, not a fabric-mass comparison.
Compare construction rather than a single number
The source describes regular fit, drawstring fastening and ribbed cuffs. Those features answer different questions from fibre composition. A drawstring does not publish a verified adjustable waist range; ribbing does not establish a measured stretch percentage or the finished leg opening.
Make the next question specific
If your decision depends on a specific component, retain style T873719B, Black Mix and 13–14 Years when contacting the seller. Ask for the current label or relevant garment measurement, not a generic cotton-rich assurance. We have not washed, stretched or worn these trousers, and cannot substitute an inferred construction test for a missing specification.
Apply it to the selected purchase
A pocket-lining claim cannot establish how the waistband is made. Keep a missing component specification open instead of filling it from a visually similar pair.
Sources & scope
Checked November 5, 2026. Manufacturer and retailer references support the specific statements. Dated displayed prices are not final checkout quotes, performance rankings or performance testing. This shopping reference does not replace the exact product label or retailer instructions. Current received labels and independent apparel/textile/content/commerce review remain pending.
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