How to Protect Dust Jackets — Mylar Covers, Handling, and Storage

For most collectible books published after 1920, the dust jacket is the single most important factor in determining value — and also the most vulnerable component. Dust jackets are thin paper wrappers designed to protect the binding, but they have no protection of their own. They tear at the edges, fade from light exposure, absorb moisture from handling, and accumulate scratches and scuffs from everyday use. Protecting dust jackets is the most cost-effective preservation measure a collector can take: a $2 Mylar cover can protect a jacket worth thousands of dollars.

Mylar Dust Jacket Covers

Mylar (a brand name for polyester film, also sold generically as polyester or PET film) is the standard material for dust jacket protection. Mylar covers are clear, chemically stable, and do not interact with paper or ink. They have been in use since the 1970s and have a proven track record of long-term compatibility with book materials.

How Mylar Covers Work

A Mylar cover slips over the dust jacket, enclosing it in a clear protective sleeve. The cover is held in place by folding over the edges of the jacket and tucking the Mylar flaps inside the front and rear boards, between the jacket flaps and the boards. No adhesive is used — the Mylar is held by friction and its own stiffness.

Choosing Mylar Covers

Thickness. Mylar covers come in several thicknesses, measured in mils (thousandths of an inch):

• 1.5 mil: Thin and flexible. Adequate for paperbacks and less valuable hardcovers. Inexpensive.
• 2 mil: The standard thickness for most collecting purposes. Provides good protection without excessive bulk.
• 3 mil: Heavy-duty. Best for valuable books that will be handled frequently or displayed. More rigid and slightly more difficult to fold.

Sizing. Covers must be sized to fit the book. The major suppliers (Brodart, Gaylord, Demco) offer covers in standard sizes — measure your book’s height and width (with jacket extended) and select the appropriate size. A cover that is too small will not fold properly; one that is too large will be floppy and may crease.

Pre-made vs. rolls. Pre-made covers are pre-cut to standard sizes and require minimal trimming. Roll stock is more economical for large collections but requires cutting each cover to size.

Applying Mylar Covers

1. Work on a clean, flat surface. Dust and debris on the work surface can scratch the jacket.
2. Remove the dust jacket from the book.
3. Center the jacket on the Mylar. The Mylar should extend equally beyond the top, bottom, and sides of the jacket.
4. Fold the Mylar over the top and bottom edges of the jacket. Crease firmly for a clean fold.
5. Fold the Mylar over the jacket flaps. These folds should wrap around the edge of the jacket and tuck inside.
6. Replace the jacket on the book, tucking the Mylar flaps between the jacket flaps and the boards.
7. Adjust for a snug fit. The cover should be smooth and flat, with no wrinkles or air bubbles.

What Not to Use

Cellophane. Not the same as Mylar. Cellophane yellows, becomes brittle, and can adhere to the jacket surface. Never use cellophane tape or cellophane wrap on a dust jacket.

PVC (vinyl) covers. PVC outgasses chemicals that can damage paper and ink. It should never be in contact with collectible materials.

Self-adhesive book covers. Contact paper, adhesive laminate, and self-sticking covers bond permanently to the jacket surface. Removing them tears the jacket. Never apply adhesive covers to collectible dust jackets.

Rubber bands. Rubber deteriorates, stains, and leaves permanent marks on paper. Never hold a jacket in place with a rubber band.

Handling Dust Jackets

General Principles

Clean, dry hands. Oils, moisture, and dirt from hands transfer to jacket surfaces. Wash and dry your hands before handling jackets, particularly uncoated or matte-finish jackets. Some collectors wear cotton gloves, though this is more common in institutional settings.

Support the book. When examining a jacketed book, support it from below. Do not let the book hang from its jacket — the weight can tear the jacket at stress points.

Open carefully. When opening a jacketed book, let the covers fall open naturally. Forcing the covers open strains the jacket at the spine.

Remove the jacket for extended reading. If you intend to read a collectible book, remove the dust jacket first and store it flat in a protective Mylar cover. Reading with the jacket on subjects it to repeated handling stress.

Removing a Book from the Shelf

The most common source of dust jacket damage is poor technique when removing a book from a shelf. The natural impulse is to hook a finger over the top of the spine and pull. This tears the head of the jacket — and eventually the head of the binding.

Correct method: Push the books on either side back slightly, then grasp the book by the sides of the text block (not the spine) and slide it forward. Alternatively, press down on the top of the text block to tilt the book forward, then grasp it.

Shelving and Storage

Upright Storage

The standard storage position for hardcover books is upright on a shelf, spine out. For jacketed books:

• Shelve books upright, not leaning. Leaning books put stress on the spine and jacket.
• Use bookends to keep books vertical without squeezing.
• Do not pack shelves so tightly that books must be forced in or pulled out.
• Leave the Mylar cover on while shelved.

Flat Storage

Very large books (folios, art books), very fragile books, and books with delicate jackets may be stored flat. Stack no more than 3–4 books to avoid crushing the bottom books.

Avoiding Light

UV light (from sunlight and fluorescent bulbs) fades dust jacket inks — particularly red, yellow, and blue pigments. The spine panel, which faces outward on a shelf, is most susceptible.

Protection measures:

• Position bookshelves away from windows and direct sunlight
• Use UV-filtering glass on any display cases
• Replace fluorescent bulbs with LED lighting (lower UV output)
• Rotate displayed books periodically to distribute light exposure

Temperature and Humidity

Paper and ink are stable across a moderate range of conditions:

• Temperature: 65–72°F (18–22°C). Avoid spaces with extreme heat or cold.
• Humidity: 30–50% relative humidity. High humidity promotes foxing and mold; low humidity causes paper to become brittle and crack.
• Stability: Avoid rapid fluctuations in temperature and humidity, which cause paper to expand and contract, stressing fibers and adhesives.

Repairing Damaged Dust Jackets

When to Repair

Minor damage — small tears, creases, light soiling — is generally best left alone on collectible books. The risk of making damage worse through amateur repair outweighs the aesthetic improvement. For books worth more than a few hundred dollars, consult a professional conservator before attempting any repair.

Acceptable Repairs

Archival tissue repairs. Small tears can be stabilized by applying thin Japanese tissue (kozo) with wheat starch paste to the inside of the jacket. This prevents the tear from extending while remaining reversible.

Cleaning surface soil. Light surface dirt can sometimes be removed with a soft eraser (vinyl or gum) applied gently. Test on an inconspicuous area first.

Never Acceptable

Cellophane tape. Tape yellows, stains, and damages paper permanently. Tape residue is extremely difficult to remove. Never tape a dust jacket.

Glue. Standard household glue (Elmer’s, super glue, hot glue) damages paper and is not reversible. Only archival-grade wheat starch paste or methyl cellulose should be used for paper repair.

Trimming. Cutting away damaged edges to make the jacket look neater reduces the jacket’s original dimensions and constitutes alteration that must be disclosed in any sale.

Color touch-up. Painting, marking, or digitally printing over faded or damaged areas is considered restoration. It must be disclosed to buyers and reduces value in most cases.