Preserving AV Materials: A Practical Guide

Audio and visual materials are some of the most fragile formats in our collections. Whether you're managing a community archive, overseeing a museum collection, or simply preserving family memories, it’s important to understand how these materials work and what they need to survive. This guide offers a practical overview of how to handle, store, and preserve physical AV materials, from early wax cylinders to VHS tapes.

Understanding AV Formats

Sound recording technology dates back to the 1870s. It started with wax cylinders and evolved into shellac discs, vinyl LPs, and compact cassettes. Video came on the scene in 1891 with nitrate film, which was highly flammable and eventually replaced by safer materials like polyester. Archives today commonly hold 16mm and 35mm film, VHS tapes, audio reels, and other formats that are increasingly obsolete but rich in historical content.

While this blog focuses on physical AV materials, it's worth noting that most formats were not designed to last forever. Environmental stability, gentle handling, and appropriate storage are critical.

Environmental Control Is Everything

Sound and video materials are extremely sensitive to temperature and humidity. The best environment for long-term preservation is cool and dry. Aim for:

• Temperature: 60 to 68 degrees Fahrenheit

• Relative Humidity: 40 to 45 percent

• Avoiding Fluctuations: It’s better to be consistently warm than to swing between cold and hot

• Rodent and Pest Protection: Packaging, especially paper sleeves, attracts pests

Humidity and temperature changes can speed up deterioration. Sticky shed syndrome, mold, and warping are all common signs that something is wrong.

Handling with Care

Nearly all AV formats require individual handling. Materials made before the 1940s are especially brittle and can shatter with a drop. Always use two hands to hold items, especially vinyl and shellac discs. Never stack discs or tapes. Keep fingers away from playing surfaces, and when handling film, use nitrile gloves rather than cotton.

Format by Format Tips

Wax Cylinders

• The earliest commercial sound recording format

• Extremely fragile and should be handled as little as possible

• Store upright in a box that separates the cylinder from the container

Shellac and Vinyl Discs

• Shellac discs are heavy and brittle, common from the 1920s to 1940s

• Vinyl records are more durable but easily warped by heat

• Store vertically in acid-free sleeves and boxes, using shelving that can bear the weight

• Keep away from direct light and extreme temperatures

Magnetic Tape: Reel-to-Reel and Cassettes

• Open-reel tape is unprotected and collects dust and mold easily

• Tapes must be wound tightly and evenly to avoid damage

• Compact cassettes are extremely vulnerable to magnets and high humidity

• Store upright, not stacked, and transfer content to new formats as soon as possible

Video Cassettes

• Includes formats like Betamax, VHS, and Sony U-matic

• Vulnerable to sticky shed syndrome, where layers of the tape absorb moisture and stick

• Always store vertically and avoid environments with changing humidity levels

Optical Media: CDs and DVDs

• Data is read by laser rather than through physical contact

• Susceptible to scratching and warping

• Separate discs from paper inserts

• Store in jewel cases or acid-free sleeves and always back up any unique content

Motion Picture Film: 8mm, 16mm, 35mm, and Super 8

• Handle film by the edges only, wearing nitrile gloves

• Use archival cans for storage, one reel per can

• Secure the end of each reel with acid-free paper tape

• Watch for vinegar syndrome, a strong odor indicating serious chemical decay. If detected, open the canister carefully, waft the air toward your nose to check, and get the film to a professional right away. There’s no way to reverse it

Playback Equipment and Risks

If you plan to view or listen to AV materials, it’s essential to use archival-quality playback equipment. This means machines that support a range of sizes and have the correct stylus shape and condition. Poor-quality or damaged equipment can permanently destroy a disc or tape. Limit playback and handling overall. Just because it plays once doesn't mean it will survive playing again.

Reformatting and Migration

No physical AV medium is forever. Reformatting is the process of copying content to a new, more stable medium. Ideally, you should create two versions:

• Master Copy: High-quality file used for preservation

• Access Copy: Used for public viewing, listening, or research

Work with professional vendors when possible. While consumer digitization equipment may be fine for CDs or DVDs, magnetic tape and film are often best left to experts.

Don’t Ignore It

AV materials can feel overwhelming, especially when playback machines are long gone or the materials seem too delicate to touch. But ignoring them won’t stop deterioration. Make sure they are stored in a stable environment, handle them with care, and think seriously about digitizing unique or at-risk items.