Comic Book Storage and Preservation — Bags, Boards, and Beyond

Comic books are among the most fragile collectibles — printed on cheap newsprint, bound with staples, and originally intended to be read once and discarded. Preserving them in collectible condition requires deliberate, systematic storage practices. The difference between a comic stored properly for decades and one stored carelessly can be multiple grade points — and tens of thousands of dollars for key issues.

Bags and Backing Boards

Why Bags Matter

Bags protect comics from three primary threats:

• Dust and dirt — particulate matter that settles on covers and causes surface abrasion
• Moisture — humidity that promotes foxing, mold, and paper degradation
• Handling — the bag provides a buffer against fingerprints, oils, and accidental damage during handling

Types of Bags

Polypropylene bags — the current standard for comic storage. Polypropylene is:

• Crystal clear (excellent display visibility)
• Chemically inert (will not off-gas or react with the comic)
• Moisture-resistant
• Durable
• Available in standard sizes for current (post-1980), Silver Age, and Golden Age comics

Mylar (polyester) bags — the premium option. Mylar (specifically Du Pont’s Mylar D or equivalent) is:

• Archival quality (will not degrade for centuries)
• Completely inert
• Rigid enough to provide some structural support
• Significantly more expensive than polypropylene
• Recommended for high-value comics

Polyethylene bags — an older, less expensive option that is still widely used. Polyethylene is chemically safe but less clear than polypropylene and tends to wrinkle over time. It should be replaced every 3–5 years as it degrades.

Backing Boards

Backing boards are stiff cardboard rectangles placed behind the comic inside the bag to provide structural support, preventing bending, curling, and spine roll.

Acid-free boards — the only acceptable choice. Boards containing acid will leach into the comic over time, causing browning and deterioration. Look for boards labeled “acid-free” or “archival.”

Half-back boards — boards that are acid-free on the side touching the comic but may not be acid-free throughout. These are a cost compromise but less ideal than fully acid-free boards.

Sizing

Bags and boards come in standard sizes:

• Current (post-1980) — 6 7/8” x 10 1/2” bag
• Silver Age (1956–1980) — 7 1/8” x 10 1/2” bag
• Golden Age (1938–1956) — 7 5/8” x 10 1/2” bag
• Magazine — for oversized comics, treasury editions, and magazines

Using the correct size prevents the comic from shifting inside the bag (too large) or being compressed (too small).

Storage Boxes

Short Boxes and Long Boxes

Comics in bags and boards are stored upright in comic storage boxes — corrugated cardboard boxes designed specifically for comic storage:

Short boxes hold approximately 150–200 bagged and boarded comics. They are easier to handle (lighter when full) and better for organizing by title or run.

Long boxes hold approximately 250–300 bagged and boarded comics. They are the standard for large collections and dealers but are heavy when full (40–50 pounds).

Box Quality

Use boxes specifically designed for comic storage — they are the correct dimensions, made from sturdy corrugated cardboard, and have reinforced handles. Do not use random cardboard boxes, which may be the wrong size, insufficiently sturdy, or made from acidic materials.

Orientation

Store comics upright (vertically) in boxes, like files in a filing cabinet. Do not stack comics flat on top of each other — the weight of the stack compresses the bottom comics, causing spine stress and cover indentation.

Comics should be snug enough in the box that they do not lean or fall over, but not so tightly packed that removing one comic damages its neighbors. Use box dividers or spacer boards to fill partially empty boxes.

Environmental Controls

Temperature

65–72°F (18–22°C) is the recommended range. Higher temperatures accelerate chemical degradation (paper yellowing, adhesive deterioration) and can soften inks.

Humidity

40–55% relative humidity is ideal:

• Below 30% — paper becomes brittle
• Above 65% — mold, foxing, and insect risk increases dramatically

Use a hygrometer to monitor humidity and a dehumidifier in damp environments.

Light

Store comics in darkness. Light — especially ultraviolet light — causes:

• Cover fading (one of the most common and irreversible forms of damage)
• Paper yellowing and embrittlement
• Ink degradation

Never display valuable comics in direct sunlight or under fluorescent lighting. If you display comics, use UV-filtering frames and rotate displayed issues regularly.

Air Quality

Avoid storing comics in:

• Basements — prone to dampness, flooding, and temperature extremes
• Attics — prone to extreme heat, cold, and humidity swings
• Garages — exposed to automotive fumes, dust, and temperature extremes
• Near kitchens — cooking fumes and grease

The ideal storage location is an interior room (no exterior walls) with climate control, away from windows and water sources.

CGC Slabs

Encapsulated Storage

Comics graded by CGC or CBCS are encapsulated in hard plastic cases (“slabs”) that provide:

• Physical protection from bending, tearing, and handling damage
• A sealed environment that limits exposure to humidity and pollutants
• Authentication and standardized grading

Slab Storage

Slabbed comics require different storage than raw comics:

• Store slabs upright in boxes or on shelves designed for their dimensions
• Do not stack slabs more than a few high (the weight can crack lower cases)
• Keep slabs away from extreme heat (which can warp the plastic) and direct sunlight (which can fade covers through the case)

Maintenance

Regular Inspection

Periodically inspect your collection:

• Check for signs of moisture damage (warping, foxing, mold)
• Replace bags that have become cloudy, wrinkled, or brittle (polypropylene bags should be replaced every 5–10 years; Mylar bags last indefinitely)
• Ensure backing boards have not become discolored or acidic
• Check that boxes are not sagging, crushed, or compromised

Handling

When handling comics:

• Wash and dry your hands first
• Handle by the edges, not the cover surface
• Open and close bags carefully — tearing a bag while removing a comic can scratch the cover
• Work on a clean, flat surface

Proper storage is the foundation of comic book preservation — the simple, consistent practices that protect your investment and ensure that your comics survive in the condition you value them for. The materials are inexpensive, the practices are straightforward, and the payoff is measured in decades of preserved value.