The total time a fabric or fiber sample must sit in a standard testing atmosphere (typically 65% relative humidity and 20°C) before its physical properties are measured. This ensures the material has absorbed or released enough moisture to match the ambient conditions, preventing skewed test results for weight, tensile strength, or shrinkage.
Heard on the job
Leave those denim swatches in the lab for a 24-hour conditioning time before running the tear test.
Insider tip
Natural fibers like wool and cotton require much longer conditioning times than synthetics like polyester because they absorb moisture more readily.