Nylon-Spandex Interlock for Leggings: Weight, Stretch, Recovery and Opacity

Understand the Interlock Structure

Interlock is a double-knit construction with two connected faces. In leggings it can provide a smooth surface, useful body, balanced stretch and better coverage than a lighter single-knit fabric, but these results vary with gauge, yarn and finishing.

Ask the supplier for composition, usable width, GSM, knit structure, yarn information and finishing route. Keep the approved cutting rather than approving only a digital specification.

Set Weight and Density Together

GSM helps describe mass but does not fully predict opacity or compression. Two fabrics at the same GSM can differ in density, thickness, yarn size and stretch, producing different coverage and handfeel.

Evaluate the fabric on the intended pattern and size. A dense fabric may still become transparent when overextended, while excessive weight can make a warm product unsuitable for the target climate.

Measure Stretch and Recovery

Record extension and recovery in wale and course directions using an agreed method. The pattern must be developed for the actual fabric force, not only for a stated four-way-stretch claim.

Check recovery after repeated extension and laundering. Weak recovery may lead to knee bagging, waistband movement or a loose seat even when the first fitting looks acceptable.

Approve Opacity and Surface Quality

Test squat opacity in every launch color on a defined model and size. Light colors, deep dyes and brushed surfaces can behave differently, and pocket bags or labels may become visible under stretch.

Inspect pilling, snagging, shine, needle marks and seam impressions. A very smooth face can show abrasion or construction defects more clearly than a textured fabric.

Control the Bulk Fabric

Approve shade, width, GSM, dimensional change, spirality, colorfastness and stretch recovery before cutting. Condition fabric according to the agreed production process so relaxation does not change garment measurements later.

Include the approved fabric code, color reference, lot controls, care route and test requirements in the order file. This supports repeat leggings that fit and look like the approved sample.

Relevant Product Program

Yoga Wear Manufacturing · Low MOQ Activewear · Fabric Performance Guides