Moisture Vapour Transmission Rate Testing ASTM E96
topic
Moisture vapour transmission rate testing measures the mass of water vapour passing through a fabric specimen per unit area per unit time under defined temperature and humidity gradient conditions, using either the upright cup method where a desiccant is sealed beneath the specimen or the inverted cup method where liquid water contacts the fabric underside to simulate sweating skin. The test is simpler and lower-cost than ISO 11092 hotplate measurement, making it widely used for quality control and product labelling in the commercial outerwear industry, though it does not account for the temperature-driven vapour pressure gradient that governs real in-use breathability. Results in grams per square metre per twenty-four hours are used in brand performance claims and retail specifications for breathable rainwear and sportswear.
Role
MVTR testing is the most widely used commercial breathability measurement in the apparel industry due to its simplicity and low instrument cost — enabling fabric mills and garment manufacturers to screen breathability performance in-house without specialised hotplate equipment, and providing the consumer-facing breathability ratings used in product marketing by major outerwear brands where MVTR values differentiate entry-level from premium performance waterproof breathable garments.