Four-Way Stretch How It Changes with Construction and Elastane Content
Four-Way Stretch does not stay constant when construction changes. Understanding the direction of change helps during development.
Effect of knit structure
Loop length and density move results first, usually before any yarn change is made. Working figures for Four-Way Stretch normally sit around 30-60% typical extension in mainstream production. Note ISO 13934-1 cyclic extension on the tech pack so nobody tests against an older revision.
Effect of elastane content
More elastane raises recovery but changes the value measured by ISO 13934-1 cyclic extension, so retest after any blending change. Record elastane content alongside Four-Way Stretch, because blends shift the measured value. A result outside 30-60% typical extension usually points to process drift rather than to the fibre itself.
Effect of finishing
Heat setting and softeners shift results, which explains differences between a hand sample and bulk. Keeping reference values for Four-Way Stretch lets suppliers quote without extra sampling rounds. Ask for conditioning details together with ISO 13934-1 cyclic extension, since both affect the reading.
Typical range
Working values stay around 30-60% typical extension for mainstream activewear. Working figures for Four-Way Stretch normally sit around 30-60% typical extension in mainstream production. Note ISO 13934-1 cyclic extension on the tech pack so nobody tests against an older revision.
Development advice
Change one variable at a time, then verify against ISO 13934-1 cyclic extension before moving to the next sample round. Record elastane content alongside Four-Way Stretch, because blends shift the measured value. A result outside 30-60% typical extension usually points to process drift rather than to the fibre itself.
