By Coasty Bunny, ANIMECOAST mascot


Cels are exceedingly vulnerable to high temperatures and humidity. Like all objects, they are subject to the slow process of decay. This process is considerably accelerated via exposure to UV light or absence of air circulation (the paint on the cels emit gasses, which build up and accelerate their decomposition). According to the American Institute of Conservation, ideal conditions for animation cels are as follows:


The environmental conditions are set to 62–65 F (16-18 C) and 50% (1/− 2%) relative humidity. Cels are interleaved with 2 mil polyethylene sheets and kept in archival boxes… exposure to light in every storage location has been limited.”


Always ensure that Cels remain flat. They must never be bent or rolled to avoid paint warping and cracking. Even clean hands will have trace oils and residue. Always wear cotton gloves while handling cels. Never clean them with chemicals or water. Wipe gently with a cotton or microfiber cloth.


There are differing approaches. Some research indicate Cels can be stored securely in acid-free Glassine envelopes. Other studies found polyethylene to be ideal. One area that researchers agree on: Cels must never touch as they will stick to each other and the paints will eventually fuse to the neighboring cel. All storage and mounting materials must be acid free. Glassine is not recommended for long term storage due to its biodegradability. Between polyethylene and polypropylene, it appears polypropylene is superior. Polyethylene is more flexible but polypropylene is more resistant to high temperatures, abrasive agents and chemical solvents. Cels require periodic airing-out to release their gasses. This should be done at least once yearly to quarterly (depending on sources). Polypropylene sleeves should be kept unsealed and one edge should be cut to promote airflow.

Materials and Equipment

Examples for purchase:

  • White cotton gloves

  • Acid-free polypropylene sleeves for each cel

    • BCW Treasury Resealable Comic Book Bags (10.5” x 13.5”)

  • Acid-free storage book / portfolio case (for less valuable cels)

    • Itoya Portfolio Series Art Presentation Portfolio (11” x 14”)

  • Acid-free tissue to absorb gasses (placed between polypropylene sleeves)

    • 8.5x11 Lineco buffered acid-free interleaving

    • 11x14 Buffered Acid-Free Interleaving Tissue Paper

  • Acid-free storage case (for more valuable cels; no more than 5 cels per case)

    • Lineco Clamshell Folio Boxes

    • Solander Museum Storage Case

  • Temperature and humidity controlled cabinet (more cost-effective than air conditioning)

    • Available on Amazon or ebay

    • Cigar humidors are an option