Water vapor transmission rate

Water vapor transmission rate (WVTR) measures how much moisture passes through a material over a specific period, usually expressed in grams per square meter per day (g/m²/day). It helps determine how well a material can block or allow moisture movement. Low WVTR indicates strong resistance to moisture, making it suitable for packaging or barriers that need to keep water out. Higher WVTR means the material is more permeable. Understanding WVTR helps in choosing materials for products that require moisture control, such as food packaging, electronics, or building materials.