Preserving Legacy: The Best Archival Supplies for Protecting Military Heirlooms

Relative humidity drives most preservation decisions for mixed military collections. Below 35 percent, paper and leather grow brittle and crack. Above 55 percent, mold spores activate and metals corrode. The working target many conservation labs use for mixed-material collections is 40 to 50 percent relative humidity, with temperature near 18 degrees Celsius. A drugstore hygrometer that reads to plus or minus 3 percent costs under 15 dollars and shows whether a closet, attic, or basement is already unsuitable for the objects stored there. The National Archives and Records Administration publishes preservation guidance built around this band, and it applies to a 1944 ration book as much as to a brass cap badge.

Ordinary cardboard and most consumer paper sit between 4 and 5 on the pH scale. That is acidic enough to yellow and embrittle adjacent paper within a single decade through acid migration. Archival paper products carry a pH between 7 and 8.5 and often include a calcium carbonate buffer that neutralizes acids as they form. Product labels should say buffered, acid-free, lignin-free. All three terms matter, and lignin-free is the one most often absent.

Why lignin does so much damage

Lignin is the compound that gives wood its rigidity, and it remains in paper that has not been chemically purified. Light and oxygen break it down into acidic byproducts, which is why old newsprint turns brown and brittle. A wartime letter written on cheap pulp paper already contains its own acid load, so the folder or box around it should avoid adding more.

Paper usually benefits from buffered enclosures with a calcium carbonate reserve. Protein-based materials need different treatment: wool uniforms, silk regimental flags, leather, and most black-and-white photographs can be damaged by an alkaline buffer. Conservators at the Library of Congress draw that distinction plainly: buffered supplies for documents, unbuffered tissue and boxes for textiles and photographs. A 25-dollar buffered box used for a silk sleeve insignia can yellow the fabric in a permanent way.

Storing letters so the ink survives the paper

Correspondence is often the most fragile part of a service collection and the hardest to replace emotionally. A field letter from 1943 kept in its original folds has weakened fibers along the crease lines, and each refold worsens the breaks. Unfold the letter once, flatten it gently, and keep it flat.

Use acid-free folders rated to ISO 9706 or the stricter ISO 18916 photographic standard. Choose a size that fully supports the sheet so no edge overhangs the folder.

If the ink is iron gall, use unbuffered acid-free tissue for interleaving. Iron gall ink, the dark brown ink common before mid-century, is itself acidic and corrodes the paper beneath it over time.

Polyester sleeves made from uncoated polyethylene terephthalate, sold under the trade names Melinex or Mylar D, let a letter be handled without direct contact. PVC sleeves should stay out of archival storage. The plasticizers that keep PVC flexible off-gas hydrochloric acid, and the greasy residue they leave can bond to ink.

Gaylord Archival, Hollinger Metal Edge, and University Products dominate this market in North America. All three publish test data, including the Photographic Activity Test, or PAT, that separates genuinely archival enclosures from products that only use the word archival.

A box of 100 letter-size acid-free folders runs roughly 30 to 45 dollars depending on weight. Store those folders upright in a buffered document box. Flat stacks put crushing weight onto the lower sheets and press old creases back into the paper.

Shadow boxes for medals need real depth

Most retail shadow boxes are 19 to 25 millimeters deep inside. That works for a flat ribbon bar, but it fails for a campaign medal hanging 8 millimeters proud of its mount. If the medal touches the glass, condensation on that glass becomes the corrosion site. For medals with suspended pendants, look for at least 38 millimeters of interior depth, and allow more for a folded flag or beret.

Standard glass blocks almost no ultraviolet light. UV fades ribbon dye and degrades fabric backing. Conservation-grade acrylic such as Tru Vue Optium, or UV-filtering glass, blocks 97 to 99 percent of ultraviolet light. On a 30 by 40 centimeter frame, the upgrade often adds 40 to 90 dollars over plain glass. That part of the frame has a direct bearing on whether ribbons keep their color over the next 30 years.

Mounting fabric and backing board need archival specifications too. A medal pinned to craft-store foam-core rests against acidic material that can outgas onto the metal. Use acid-free mat board or a covered conservation board, and secure medals with cotton thread or stainless steel pins. Adhesive is the wrong mount for medals.

Brass and bronze medals develop a stable protective patina when left undisturbed. Polishing removes original metal and can soften or erase maker’s marks struck into the surface. A medal polished bright is worth measurably less to collectors than one with its original surface intact, and the patina is providing protection.

Exterior walls create avoidable stress for display cases. Temperature shifts across the wall surface can drive daily condensation cycles. An interior wall away from heating vents holds steadier conditions and costs nothing.

Gloves are not always safer

The white cotton glove has become a preservation symbol, but it is often a poor choice for coins, medals, and metal objects. Clean dry hands or nitrile gloves give better grip and reduce drop risk because cotton snags and dulls tactile feedback. Cotton gloves remain appropriate for photographs and unstable paper.

Photographs need PAT-tested enclosures

Color service photographs from the 1960s through 1990s fade because their dye couplers are inherently unstable. Heat accelerates that fading. Every drop of about 5 degrees Celsius roughly doubles dye lifespan, and cold storage at refrigerator temperature, in sealed bags conditioned to low humidity, can extend color print life by decades in conservation literature.

For ordinary storage, the enclosure should pass the Photographic Activity Test, ISO 18916, which screens for chemical interactions between the enclosure and the image. Paper enclosures for photographs should be unbuffered, unlike the buffered folders used for many documents. Plastic enclosures should be uncoated polyester, polypropylene, or polyethylene. PVC has the same acid and residue problems here that it has with documents.

Polyester sleeves have one specific risk. A print with cracked or flaking emulsion should not be slid into a tight polyester sleeve, because static cling can lift the emulsion from the paper base.

Scan fragile prints at 600 dpi to create an access copy for handling and sharing while the original stays in cold, dark, stable storage. The original continues to degrade, but each avoided retrieval also avoids abrasion to the image surface.

The sorting problem no box solves

A linen field cap stored perfectly at 45 percent humidity in unbuffered tissue still loses tensile strength each year, just slowly enough that the loss may outlast its owner. The same problem applies across paper, textiles, metals, and photographs: storage buys time, with different costs for different objects.

The supply list cannot decide which artifact deserves cold storage and conservation glazing. Which objects should remain available for careful viewing, and which should be kept chiefly through the record made from them?