Interlock Fabric Specification for Sportswear: Anti-Curling, GSM and Sample Approval

Interlock is a double-knit construction, but that name alone is not a complete buying specification. Two interlock fabrics can differ in GSM, yarn, surface, openness, stretch and finishing. Buyers should define the garment job and measure the points that affect cutting, sewing, coverage and wear before they compare samples.

What belongs in an interlock sportswear specification?

Begin with the finished garment and the zones where interlock will be used. A lightweight top, a structured panel and a lining may all need a different balance of cover and stretch. Put the requested range in writing so the sample can be judged against the same reference.

• construction and fibre composition
• target GSM range and usable width
• face appearance, cover and opacity under tension
• stretch direction, recovery expectation and finished dimensions
• colour, print or finishing requirement

How should GSM and cover be checked?

GSM is useful only when the sample condition and tolerance are clear. Record the measured weight, usable width and any relaxation or finishing condition used for the measurement. Then check cover in the relaxed state and at the stretch used by the garment, because a fabric that looks opaque on the table may become more open in wear.

These are listed product examples, not a universal interlock GSM standard. Review the 145 GSM pin-dot-hole interlock, 160 GSM interlock mesh and 270 GSM bird-eye interlock against the actual garment brief.

How can a buyer check anti-curling behaviour?

Anti-curling is a sample and process check, not a label that should be accepted without observation. Inspect the cut edge after relaxation, handling and the intended wash or finishing route. Check whether the edge rolls differently in the wale and course directions, and record the result alongside the cutting and sewing trial.

• relax the sample for the same period used in the buyer's cutting process
• cut test strips in both principal directions
• observe edge curl before and after handling or washing
• record the sewing machine, seam allowance and thread setup used for the trial
• agree an acceptance description or measurement before bulk release

What should the sample-to-bulk approval include?

Approve the complete fabric behaviour, not only the swatch colour. Keep the signed or otherwise controlled reference with the measured specification, garment trial notes and any test reports. If a tolerance is still open, mark it as open and assign the next confirmation instead of silently treating the sample as a fixed standard.

• construction, composition, GSM and usable width
• stretch and recovery direction with the garment trial result
• edge behaviour, cut quality and seam appearance
• shade, print, wash or finishing approval
• inspection plan and action for out-of-range lots

When is interlock the right shortlisting direction?

Interlock is worth shortlisting when the garment needs a stable double-knit body, controlled cover or a specific surface and weight. It should not be selected only because the word sounds more substantial. Compare it with mesh, jersey or tricot when airflow, drape, stretch or print response is the main decision.

For a wider construction comparison, the tricot versus interlock sourcing guide covers the broader distinction. This article focuses on sportswear specification and approval checks.

What to include in an interlock fabric inquiry

Send the garment or panel role, target GSM and width range, construction preference, stretch direction, cover requirement, colour or print method, expected quantity and sample timing. Ask the supplier to identify standard options separately from custom development and to state which points still need testing.

When the brief is ready, send it to the fabric inquiry team. Any GSM, MOQ, price, lead time or performance value should be confirmed for the selected construction and order, not presented as a universal promise.