3M™ Vent Tape 394 is a 4 mil white non-woven synthetic tape that permits air and gas to pass through while blocking liquids and foam bleed-through. This controlled breathability combined with a pressure-sensitive adhesive distinguishes it from standard masking or sealing tapes, making it purpose-built for applications where venting during a process is critical to the finished result.

Foam-in-place insulation manufacturing is the primary application, where the tape allows gases generated during foam expansion to escape without permitting foam itself to penetrate. Appliance manufacturers rely on it to meet standard outgassing requirements during assembly. The adhesive bonds to metal, plastic, and composite substrates without mechanical fastening, making it practical on varied production-line surfaces.

Each roll measures 1-1/2 inches wide by 36 yards and is 4 mil thick. The non-woven synthetic construction maintains dimensional stability under moderate production-line tension. Cases contain 24 rolls and ship via parcel carrier.