Transparent Moisture Barrier Bag (TMBB)

 Thickness units

Mil – 0.001 inch, ex) 3 mils = 0.003 x 25.4 mm = 0.0762 mm = 76.2 microns
Micron – 1/1,000,000 m (1/1,000 mm = 0.001 mm), ex.) 100 microns = 100/25.4 = 3.93 mils
MM – 0.15 mm = 150 microns

 MVTR

The Moisture Vapor Transmission Rate (MVTR) is the rate that water vapor passes through a specific area of barrier material. MVTR is measured in grams of water vapor per 100 square inches of barrier per 24 hours (g/100 in.2/24 h). EIA 583 Packaging Material Standards for Moisture-Sensitive Items defindes a Class 1 barrier as having an MVTR of <0.02 g/100 in.2/24 h. A Class 2 barrier is set at <0.08 g/100 in.2/24 h.