Aluminum Foil - an overview | ScienceDirect
Aluminium foil is typically less than 150 µm in thickness. Foils are available in gauges as low as 6.3 µm. Heavier foil gauges (> 17 µm) provide an absolute barrier to gases and liquids. A typical water vapour transmission rate (WVTR) for 9 µm foil is 0.3 g/m 2 per 24 hours at 38 °C and 90%