4.2.2 Labels, pressure-sensitive, water-resistant. Labels shall be of a water-resistant grade of paper, film, fabric, or plastic, coated on one side with water-insoluble, permanent type adhesive. The adhesive shall adhere to metal, plastic, aluminum or fiberboard surfaces under high and low temperatures. Labels shall have a finish suitable for printing and writing on with ink without feathering or spreading, be capable of withstanding normal handling and storage conditions, and remain securely in position.
[Mil-Std-129R]
Application specific performance criteria and durability requirements to ensure functionality in various climatic environments should be tailored, if required, using MIL-PRF-61002. MIL-PRF-61002 can be used as an acquisition tool when labels presently being used are not performing satisfactorily or when new conditions or applications require special label stock for those particular situations. Identification bar code labels on exterior containers, palletized unit loads, and unpacked items shall meet the requirements of 5.4.2.1.
4.2.2.1 Use of labels. Pressure-sensitive labels that meet the requirements of 4.2.2 may be used on containers/surfaces other than wood without prior surface preparation. When pressure-sensitive labels are used on wood containers/surfaces, the labeling area shall be suitably prepared to ensure adhesion.
[Mil-Std-129R]
4.2.2.2 Protective coating of labels. If labels for exterior containers, palletized unit loads, and unpacked items, except vehicles and related items, are not inherently waterproof, they shall be waterproofed by coating the entire outer surface of the label with a transparent, waterproofing material (see 4.2.1.1). Exterior identification bar code labels shall be protected in accordance with 5.4.5.4.
Bar Code Label Printing
5.4.2 Identification bar code labels / printing. Identification linear (Code 39) bar code marking shall be printed on a label or, upon authorization by the cognizant activity, by direct printing on the packaging material. Linear (Code 39) identification bar codes can be applied directly with the identification text marking or printed onto a separate label. Stenciling of linear bar codes is not permitted. The 2D (PDF417) bar code(s) shall be printed onto label stock. Bar code labels may be accepted for use without a quality verification if they are accompanied by a certificate of conformance (COC), from the printing activity, for review by the applying/marking activity. However, the COC does not supersede the need to scan the marking after any process that may affect the readability of the bar codes, such as the application of tape.
5.4.2.1 Label stock requirements. For label stock general requirements, see 4.2.2.
a. Labels shall be constructed of a computer-imprintable media with a 1-mil acrylic permanent adhesive or equivalent.
[Mil-Std-129R]
b. When specified in the contract or purchase order, identification bar code labels generated on direct-thermal printers may be used on unit packs, intermediate and exterior containers, palletized unit loads, and unpacked items. The direct-thermal labels shall be durable, buff-colored stock, or its equivalent.
Thermal-Transfer Label Stock
The term “thermal-transfer” refers to the process by which a print head uses heat to transfer a wax ribbon to label stock. The right combination of ribbon and stock can produce very durable labels that can withstand fairly harsh environments.
These same printers can also print via a a process referred to as Direct Thermal, in which the printer darkens the label stock by applying heat directly to it. Because it is inexpensive, this technique is used extensively in commercial receipt printers. It is also popular with small parcel carriers, such as UPS and FedEx.
However, Direct Thermal labels cannot generally withstand protracted exposure to high temperatures, as they may be subjected to if stored outside in direct sunlight. Eventually the labels become dark and no longer machine-readable. For this reason, use of direct-thermal printing is permissible for contractor shipments only when specified by the contract or purchase order. See ¶5.4.2.1b above.
Protective Coatings
4.2.1.1 Waterproofing materials used as protective coatings. Waterproofing materials such as spar varnish, acrylic coating compound, sealing compound, label adhesive, polyurethane coatings, and pressure-sensitive tape that does not restrict or preclude legibility or readability of the package marking, shall be used as protective coatings on container marking.
[Mil-Std-129R]