Mylar Dust Jacket Covers — The Essential Protection for Collectible Books
If you collect books with dust jackets and do one thing to preserve them, put Mylar covers on every jacket. At $1–$3 per cover, Mylar dust jacket protectors are the most cost-effective preservation measure in book collecting. They protect jackets from handling wear, fingerprints, tears, light abrasion, and minor moisture — the everyday damages that accumulate over time and diminish both the jacket’s appearance and the book’s value.
What Is Mylar?
“Mylar” is a brand name (owned by DuPont) for biaxially-oriented polyethylene terephthalate (BoPET), a type of polyester film. In the book conservation world, Mylar refers to clear, archival-quality polyester film used for protective covers and enclosures. The key properties that make it suitable for book protection are:
- Chemically inert — does not react with paper, ink, or leather
- Transparent — does not obscure the jacket design
- Dimensionally stable — does not shrink, stretch, or warp
- No adhesive — the standard covers fold over the jacket without glue
- Acid-free — will not cause discolouration or degradation
- Long-lasting — does not yellow or become brittle with age
Types of Covers
Standard Fold-Over Covers
The most common type. A pre-cut sheet of Mylar sized to wrap around the dust jacket with flaps that fold inside the front and rear boards. The jacket is held in place by the tension of the folds — no adhesive is used.
Available in standard sizes to fit common book dimensions:
- Small (fits books up to approximately 8” tall)
- Medium (fits most octavo books, approximately 8.5”–9” tall)
- Large (fits taller books, approximately 9.5”–10” tall)
- Extra large (for oversize books)
Adjustable Covers
Some manufacturers produce covers with adjustable width, allowing a single cover to fit books of varying thickness. These typically have scored fold lines at multiple positions.
Custom Covers
For books that do not fit standard sizes, Mylar can be purchased in rolls or sheets and cut to size.
Application
Applying a Mylar cover takes less than a minute per book:
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Select the correct size. The cover should be tall enough to extend slightly above and below the jacket, and wide enough to fold over both the front and rear boards.
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Slide the jacket’s front flap into the front fold of the Mylar cover. Align the top and bottom edges.
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Wrap the Mylar around the front board, over the spine, and across the rear board.
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Fold the rear flap of the Mylar inside the rear board, over the jacket’s rear flap.
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Adjust for a snug, even fit. The cover should be tight enough to stay in place but not so tight that it distorts the jacket.
The cover can be removed at any time without damaging the jacket — the process is completely reversible.
Where to Buy
Major suppliers of archival Mylar dust jacket covers include:
- Brodart — one of the largest suppliers, with a wide range of sizes
- Gaylord Archival — conservation-grade supplies
- University Products / Archival Products — specialist conservation supplier
- Amazon — various brands available, though verify archival quality
Buy in bulk (packs of 25 or 50) for significant savings. The cost per cover drops to approximately $1 or less in quantity.
What Mylar Covers Protect Against
Handling wear. Every time a book is picked up, shelved, or examined, the jacket experiences friction. Mylar transfers that friction from the jacket surface to the cover surface.
Fingerprints and oils. Skin oils can stain dust jackets over time. The Mylar barrier prevents contact between hands and the jacket.
Minor tears. The Mylar reinforces the jacket edges, reducing the likelihood of tears at the spine head and foot.
Light abrasion. Books shelved next to each other rub together. Mylar prevents this contact from wearing the jacket surface.
Minor moisture. A small spill or splash that would stain an unprotected jacket is deflected by the Mylar cover.
Dust and dirt. The cover keeps environmental dust off the jacket surface.
What Mylar Covers Do NOT Protect Against
Sunlight and UV. Standard Mylar is transparent to ultraviolet light. It does not prevent fading from sunlight or fluorescent light. Books should still be shelved away from direct light.
Major water damage. Mylar protects against splashes but not flooding or sustained water exposure.
Temperature and humidity. Mylar does not regulate the storage environment.
Physical impact. The thin film does not protect against crushing, bending, or heavy impact.
Should Every Book Get a Cover?
Yes, if it has a dust jacket and you want to preserve its value. The cost is trivial relative to the value of even a moderately collectible book. A $2 Mylar cover protecting a $200 dust jacket is an investment with an immediate and permanent return.
Exceptions: Books without dust jackets obviously do not need them. Books in fine bindings (full morocco, etc.) may benefit from phase boxes or cloth wrappers rather than Mylar. Very large or irregularly shaped books may not fit standard covers and may require custom solutions.
The habit of covering every new acquisition immediately upon shelving is one of the simplest and most effective practices a collector can adopt. The cumulative protection over years and decades is substantial — and the slight sheen of the Mylar cover on a well-kept shelf is itself a satisfying signal of a collection that is cared for.