Shrinkage Above Contract, a Shade Bar and a Marker Two Centimetres From the Selvedge
An export order for 1,200 men's cotton poplin shirts must ship in 14 days. The fabric arrived as three rolls totalling 3,000 m; roll 2 carries a shade bar about 180 m from its start. The supplier's contract states maximum shrinkage 2%, but your laboratory reports 3.8% warp and 2.1% weft after five home launderings at 40 °C. Fabric width is 112 cm; the approved marker for the largest size is 108 cm wide and the lay is planned at 60 plies. The buyer's tolerance on chest is ±1 cm and on body length +1.5/−0 cm. The pattern was graded to finished garment measurements with no shrinkage allowance. There is no time to source replacement fabric, and part of the fabric has already been cut for the sample room.
1. Decide what to do about the shrinkage result. Show the calculation that drives your decision and the options you reject.
Read the worked answer
Translate percentage into millimetres on the garment. A shirt with body length 76 cm shrinks 3.8% warp = 2.9 cm - nearly double the permitted 1.5 cm. Chest, say 110 cm finished circumference, shrinks 2.1% weft = 2.3 cm, i.e. 1.15 cm per half-chest against a ±1 cm tolerance. So the lot as patterned cannot meet the buyer's tolerance after washing. The pattern has no allowance, so nothing compensates for this.
Options, evaluated:
- Do nothing and ship - rejected: the garment will fail the buyer's wash test, and the claim will exceed the order value.
- Reject the whole lot and re-source - not possible in 14 days; also the fabric is partly cut.
- Add shrinkage allowance to the pattern - this is the workable route, but it must be computed per size from the actual shrinkage and confirmed by a garment wash test (sew, wash at the buyer's stated conditions, re-measure, adjust). The allowance is applied to length and width separately (3.8% and 2.1%), never as a flat percentage.
- Ask the supplier for a price credit or debit note for out-of-spec material - do this in parallel; it does not solve the technical problem but recovers margin.
- Pre-shrink/compact the fabric - check whether the mill can do it in the time available; if not, reject.
Additionally, test each roll separately, because one lot with three rolls can show three different shrinkage values; mixing them in one lay gives you a size problem you cannot correct afterwards.
2. Explain how you would spread and cut the three rolls so that the shade bar does not become a visible shade difference in a finished shirt.
Read the worked answer
The principle is that all plies that become one garment must come from the same shade group, and the shade sequence must be documented and traceable.
Plan:
- Shade-sort before spreading: unroll enough of each roll in daylight or under a D65 light box and compare ends against a master swatch. Give each continuous length a shade group number (1, 2, 3…). Roll 2 becomes two groups - before and after the bar.
- Spread by group, not by roll: do not complete a lay by jumping into the next shade group to reach 60 plies. If the group has only 40 plies of usable length, cut a 40-ply lay and make up the balance with a separate lay of the next group.
- Keep it short in shade-critical parts: front, back, collar, yoke and sleeves must be same group. Small parts - pocketing, interlining, inside facings - can cross groups if the buyer permits.
- Identify and bundle: number each ply, ticket the bundle with roll number, shade group and lay number, and keep the bundle intact to the sewing line. Never top up a bundle from another group when a piece is short.
- Control at sewing: the line supervisor checks that the collar, cuff and body of one shirt carry the same group ticket. A shade bar that reaches the customer is almost always a bundling failure, not a spreading failure.
Record the roll map (metres used per group) so that if a claim comes back you can trace the shirt to the exact length of fabric.
3. The marker is 108 cm on a 112 cm fabric. Is that acceptable? State the checks you would make before releasing the lay, and the preparation steps the fabric needs first.
Read the worked answer
Two centimetres of clearance per side is tight and should not be released without checks. Four centimetres of total margin has to absorb selvedge damage, pin or clip marks, and above all bowing and skewing of the weft, which is common in cotton poplin and which a straight-edged marker cannot follow. On a 60-ply lay, a skewed weft produces panels cut off-grain, and the shirt will twist after washing - a defect that appears long after the fabric is consumed.
Checks before release:
- Measure the usable width after trimming damaged selvedge on a sample from each roll; if usable width falls below about 110 cm, redraw the marker to 106–107 cm.
- Check bowing: mark a weft line across the roll at three places and measure the deviation. If it exceeds roughly 1 cm, spread face-to-face in shorter lays or use a bowed marker.
- Check that no pattern piece encroaches into the outer 1 cm of either side.
- Confirm the marker is the approved one and that the grain line is parallel to the selvedge.
Fabric preparation:
- Give the rolls relaxation time in the cutting room (typically 24 hours, unrolled or loosely rolled) so that the fabric that was stretched on the roll can recover before it is cut.
- Cut after relaxation, not before, otherwise every panel shrinks after cutting and the size is lost.