MIL-PRF-121G Specification

121 G is the most recent revision of the military specification that defines the requirements that waterproof, greaseproof and heat-sealable flexible barrier packaging must meet to preserve military equipment and supplies.

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MAC Packaging has been the industry leader in military packaging and supplies for government contractors since 1976. The barrier materials covered by this specification are intended for use in specialized military methods of preservation, and are available in different quantity so please contact us for specifications needed.


This specification establishes the requirements for heat-sealable, greaseproof, waterproof, flexible barrier material used for the preservation of military supplies and equipment.
* Barrier materials shall be made from such materials and by such processes as to ensure compliance with the performance requirements of this specification.
* The barrier materials shall be constructed of one or more piles in any manner that ensures compliance with the performance requirements of this specification.
* A roll shall contain no more than 2 splices (3 pieces). Splices within rolls shall be even, extend the entire width of the roll, and shall not come apart during unwinding of the roll. Splices shall be flagged at both ends of each splice with colored markers.
* The barrier material shall be furnished in rolls.
* The material shall exhibit no delamination of the heat-sealed area when sealed according to the manufacturer’s recommended conditions. Each roll of barrier material shall include a tag secured to the roll core with the sealing instructions for heat-sealing on continuous and jaw-type sealing equipment. The tag shall be visible upon opening the unit.
* Identification of the material will include the specification number, type, manufacturer’s name and designation, month and year of manufacture, and lot number shall be clearly and legibly marked using water-resistant ink on the backing surface of the material. The color of the markings shall be red.
* Barrier material surfaces shall be free from any foreign matter. The barrier material edges shall be cut and trimmed of any selvage. Barrier material shall be free from holes, tears, cuts, sharp creases, wrinkles, or other imperfections.


MIL-SPEC Contracts

We have earned our enviable industry reputation in part because of our four decades of experience and knowledge of the U.S. Department of Defense’s detailed military packaging specifications and regulations.

MIL-SPEC Labeling

We are experts in the complex military packaging and labeling requirements. We make sure your package gets delivered to it’s desired location on-time at a lower cost than you can do yourself.

Adminstrative Requirements

We can communicate with contract officers, facilitate inspections and help maintain accurate data in the governments electronic systems to assure delivery acceptance and timely payment of your invoices.
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