Fabric Weight per Unit Area Measurement
topic
Fabric weight measurement per ISO 3801 cuts circular or square samples of defined area from fabric conditioned at 20 degrees Celsius and 65 percent relative humidity, weighing to the nearest milligram and expressing weight as grams per square metre, with the measurement being performed at multiple width and length positions to assess weight uniformity, and with weight comparison against specification identifying whether the fabric meets the contracted GSM specification and whether weight variation indicates process parameter instability.
Role
Provides the most widely used and commercially significant fabric specification parameter that determines material cost per metre, garment weight, end-use suitability, and the primary commercial quality descriptor in most fabric purchase contracts, with GSM measurement being performed at every stage from loom output through finishing to final inspection and with GSM specification compliance being the fundamental acceptance criterion that determines whether fabric can be sold at the contracted price.