How to Store and Preserve Comic Books — Bags, Boards, Boxes, and Climate Control

Comic books are inherently fragile. They are printed on newsprint — acidic, wood-pulp paper designed for disposable reading, not long-term survival. Without intervention, the paper yellows, becomes brittle, and eventually crumbles. Proper storage slows this degradation dramatically, preserving both the physical comics and their value.

The Essential Supplies

Bags

Every comic in your collection should be in a bag. Bags protect against handling wear, dust, moisture, and fingerprints.

Polypropylene bags — The current standard. Chemically stable, crystal-clear, and inexpensive. They do not outgas harmful chemicals and maintain clarity for years.

Mylar bags (polyester) — The conservation-grade option. Mylar is more durable, completely inert, and will not degrade over time. More expensive (roughly 5x the cost of polypropylene) but recommended for valuable comics.

Polyethylene bags — The older standard. Less clear than polypropylene, softer, and more prone to clouding over time. Adequate but not preferred.

Sizing: Bags come in standard sizes matching comic book eras:

• Current size (6 7/8” × 10 1/2”) — for comics from the 1990s onward
• Silver Age size (7 1/8” × 10 1/2”) — for comics from the late 1950s–1980s
• Golden Age size (7 5/8” × 10 1/2”) — for larger Golden Age comics
• Magazine size — for oversized comics and magazines

Backing Boards

A stiff acid-free board placed behind each comic inside its bag. Backing boards:

• Prevent bending and creasing
• Provide structural support
• Buffer acid migration from the comic’s own paper

Acid-free boards are essential. Standard cardboard boards contain acid that accelerates paper degradation. Always buy boards explicitly labelled “acid-free.”

Boards come in the same size classifications as bags (current, Silver Age, Golden Age).

Storage Boxes

Short boxes hold approximately 150–200 comics. Manageable weight (approximately 25–35 lbs full), easy to stack, and the most common storage unit.

Long boxes hold approximately 250–300 comics. Heavier when full (40–50 lbs), more efficient per box but harder to move.

Both should be made of corrugated cardboard. Some collectors upgrade to acid-free or plastic storage boxes for maximum protection.

Stack boxes no more than 3–4 high to prevent crushing. Store on shelves or pallets — not directly on concrete floors (moisture wicks through concrete).

The Storage Process

1. Place the comic in a correctly sized bag with an acid-free backing board behind it
2. Fold the bag flap over (do not tape it closed — tape can damage the comic if the bag is opened carelessly)
3. Stand comics upright in boxes, snugly but not tightly packed
4. Fill any empty space at the end of a row with a piece of acid-free foam board to prevent comics from leaning

Environmental Controls

Temperature

Ideal: 60–70°F (15–21°C). Higher temperatures accelerate chemical degradation. Avoid attics, garages, and any unclimate-controlled space.

Humidity

Ideal: 40–50% relative humidity. High humidity promotes mould, foxing, and paper warping. Low humidity makes paper brittle. A dehumidifier in the storage room is essential in humid climates.

Light

Ideal: minimal to none. UV light causes fading and paper degradation. Store comics in closed boxes, in rooms without direct sunlight. Never display valuable comics in frames exposed to sunlight.

Handling

• Wash and dry hands before handling comics
• Hold comics by the edges, not the cover surface
• Open bagged comics over a clean, flat surface
• Do not eat, drink, or smoke near comics
• Use a flat, clean reading surface — never bend a comic back

Upgrading Supplies

Bags and boards should be replaced periodically:

Polypropylene bags: Replace every 3–5 years as they lose clarity and may begin to outgas Mylar bags: Essentially permanent — no replacement needed Acid-free boards: Replace every 5–10 years, especially if they show yellowing (indicating acid migration from the comic)

Common Mistakes

Storing in the attic. Extreme summer temperatures in attics can reach 130°F+, which destroys comics rapidly.

Storing in the basement. Basements are humid and prone to flooding. If you must use a basement, use a dehumidifier and store boxes on shelves, not the floor.

Using rubber bands or string. These leave permanent impressions and stains on comic covers.

Stacking comics horizontally without support. The weight of stacked comics crushes those at the bottom.

Non-acid-free materials. Using regular cardboard, newspaper, or brown paper bags in contact with comics transfers acid and causes browning.

The cost of proper storage supplies is minimal relative to the value of even a modest collection. A bag, board, and proportional box cost amounts to approximately $0.15–$0.30 per comic — insurance against degradation that would otherwise be inevitable.