Choosing a fibre blend for a school leavers' jacket
A small Sydney label is developing a unisex jacket for school leavers. The brief demands: retail price under AUD 120, machine washable, low pilling after 30 washes, and a matte finish. The designer shortlists three fabrics. Option A is 100% brushed cotton fleece at 320 gsm; it is soft and cheap but shrinks 6% in length after five washes and creases badly. Option B is a 65% polyester/35% cotton loopback knit at 300 gsm; it is dimensionally stable and cheap but has a slight sheen and pills at the cuffs. Option C is 100% merino wool jersey at 260 gsm; it drapes beautifully and resists odour but costs AUD 38 per metre, needs hand washing, and the fabric alone exceeds the budget. The factory minimum order is 500 units and the label can only fund one production run.
1. Recommend one fabric and justify the choice against all four brief criteria, acknowledging the trade-off you accept.
Read the worked answer
Option B is the defensible choice. Price: polyester/cotton loopback is a commodity knit, so at 300 gsm it lands well inside the AUD 120 retail ceiling; Option C's AUD 38/metre fabric alone blows the budget before cutting and labour. Washability: the polyester component gives dimensional stability and rapid drying, and it tolerates a normal machine cycle, unlike merino, which the brief would force into hand wash and so fails a stated criterion outright. Pilling: this is the weak point. Blending synthetic with cotton and brushing/looping the surface increases the chance of pills at high-abrasion points like cuffs. The judgement call is that pilling can be mitigated (tighter knit, longer staple, enzyme finish, pill-resistant yarn) whereas cost and washability cannot be engineered away at this price. Matte finish: the slight sheen is a cosmetic compromise, and a peach or sanded finish can reduce it. Option A fails on shrinkage (6% length loss after five washes is unacceptable for a garment sold on fit) and creasing. So B is chosen because its failures are correctable and its strengths map to the non-negotiable criteria.
2. The label's technician proposes a pill-resistance test before committing. Describe a practical test regime and explain how you would interpret a borderline result given only one production run is affordable.
Read the worked answer
A practical regime: take three specimens from different parts of the roll (selvedge, centre, end) to capture variability, subject them to an abrasion test that mimics wear at cuffs and underarm (for example a random-tumble pilling test or a Martindale-style abrasion with a defined cycle count such as 2,000 and 5,000 cycles), then assess pilling against a standard photographic rating scale from 1 (severe) to 5 (no pilling). Wash the specimens 30 times to the brief's requirement and re-rate, because pilling often peaks after several washes as loose fibres work free. Record both the rating and where pills form. Interpretation with one run: set an acceptance threshold in advance (for example, no worse than rating 3 at 5,000 cycles and after 30 washes). A borderline result (rating 3) is not automatically fatal, but it shifts risk to the customer, so the designer should either specify a tighter knit or a pill-resistant finish, or add care labelling and a small repair/returns allowance. If the result is rating 2 or below, the honest call is to reject the fabric rather than gamble the single run, because returns and reputational damage on a school-leavers' garment (high-visibility, peer-influenced market) outweigh the cost of re-sourcing.