Compression Level Test Methods and Acceptable Limits
Compression Level is verified through RAL-GZ 387 compression classes. Knowing how the method works avoids rejecting fabric that actually meets the requirement.
Method overview
RAL-GZ 387 compression classes defines sample size, conditioning and calculation, so values are comparable only within the same revision. Working figures for Compression Level normally sit around light 8-15 mmHg, firm 20-30 mmHg in mainstream production. Note RAL-GZ 387 compression classes on the tech pack so nobody tests against an older revision.
Result interpretation
Read the value together with construction notes; light 8-15 mmHg, firm 20-30 mmHg is only meaningful for similar fabrics. Record elastane content alongside Compression Level, because blends shift the measured value. A result outside light 8-15 mmHg, firm 20-30 mmHg usually points to process drift rather than to the fibre itself.
Typical limits
Buyers commonly write light 8-15 mmHg, firm 20-30 mmHg with a stated tolerance, then verify against RAL-GZ 387 compression classes. Keeping reference values for Compression Level lets suppliers quote without extra sampling rounds. Ask for conditioning details together with RAL-GZ 387 compression classes, since both affect the reading.
Sources of variation
Conditioning time, operator technique and shade all influence the result. Working figures for Compression Level normally sit around light 8-15 mmHg, firm 20-30 mmHg in mainstream production. Note RAL-GZ 387 compression classes on the tech pack so nobody tests against an older revision.
Documentation
Record the standard revision on every report, because older versions can differ from current practice. Record elastane content alongside Compression Level, because blends shift the measured value. A result outside light 8-15 mmHg, firm 20-30 mmHg usually points to process drift rather than to the fibre itself.
