School Uniform Shirting: A Substituted Yarn Count and Sett
An Odisha school uniform tender covers 8,000 m of shirting for 4,000 students. The specification is 100% cotton, 40s × 40s, 110 g/m², 110 ends/inch × 70 picks/inch, shrinkage no more than 3%, and colour fastness to washing at least grade 4. The lowest bidder delivers 30s × 30s, 140 g/m², 90 ends/inch × 50 picks/inch at the same rate, arguing that 'heavier and stronger means better value'. On opening the bale, the fabric feels stiff and boardy, and the school's tailor reports that a test shirt shrank 6% after one wash. The academic year begins in 45 days. The supplier can replace only 3,000 m within that time, against the 8,000 m ordered, and the purchase committee meets in three days. No test report has been supplied with the bale.
1. Quantify what has changed technically and explain the consequences for a schoolchild in coastal Odisha.
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The substitution changes three things at once.
Yarn linear density: 40s Ne = 590.5 ÷ 40 ≈ 14.8 tex; 30s Ne ≈ 19.7 tex, so each yarn is about one-third heavier. Sett: ends fall from 110 to 90 and picks from 70 to 50, so the cloth has fewer, thicker threads. Cover factor (threads per inch ÷ √Ne) drops from about 17.4 + 11.1 = 28.5 to 16.4 + 9.1 = 25.5 - a more open weave despite the higher mass.
Consequences: 140 g/m² against 110 g/m² is about 27% heavier, which in coastal humidity means a hotter, less air-permeable shirt. Coarser yarns give a boardy handle and poor drape. Lower sett means more yarn slippage and seam grinning. Shrinkage of 6% against a 3% limit means shirts will shrink out of fit after a few washes, and thread count will rise after the first wash, stiffening the cloth further.
'Stronger' is not established: abrasion resistance may improve, but tear and seam strength depend on sett and finishing, and no test report has been supplied.
2. Recommend a decision to the purchase committee and list the tests and conditions that should accompany it.
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Reject the bale as non-conforming, but manage the calendar.
Immediate tests on a conditioned sample: yarn count, ends and picks per inch, GSM by cutter, dimensional stability after one 40 °C wash, colour fastness to washing and rubbing, tear and seam strength, and air permeability. Ask for the mill report and verify independently at an accredited laboratory.
Options: (1) accept 3,000 m only as a separate, clearly labelled lot for sports uniforms or aprons, where stiffness and weight matter less, at a reduced rate reflecting the lower cover and the shrinkage risk; (2) source the balance 5,000 m from the second-lowest bidder, even at a small premium, with pre-delivery testing; (3) if time forces acceptance, require the supplier to compact/pre-shrink and to give a written shrinkage guarantee, and renegotiate the price.
The committee must not accept silently: the tender specification is a contract, and the decision needs test evidence and minutes.
3. Draft the procurement response: what should be communicated to the supplier and the school, and how should price be handled?
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Document and renegotiate.
Write to the supplier within 24 hours, citing the specification clauses, the 6% shrinkage result and the missing test report, and ask for a formal deviation request. Record bale number, dates and test methods so the decision is defensible in audit. The committee should minute the quantities accepted, the price adjustment, the delivery schedule and the tests to be done on the replacement lot.
Price logic: if 30s × 30s at 90 × 50 is accepted, the buyer is paying for 8,000 m of specified cloth but receiving lower-cover fabric; a fair adjustment should at least reflect the reduced sett and the finishing cost needed to bring shrinkage within 3%.
Ethically, the temptation is to accept because the school year starts soon. The correct route is partial acceptance with full disclosure to the school management, a written assurance on the balance, and a supplier performance note - not a silent substitution that leaves 4,000 students in shrinking shirts.