Invaluable clinical information
Your images contain invaluable clinical information and Logical Images doesn’t want to see it fade away. We appreciate that an image collection is the result of many years of dedicated documentation and record keeping. It is our business to preserve the integrity of your life’s work or your institution’s visual knowledgebase and to make it available for generations to come.

Factors that accelerate deterioration
Before digital photography, color transparency—or “slide” film—was the most commonly used material for visual documentation in healthcare settings. This is not surprising as slides have excellent image quality, are easy to store because of their small size and can be projected to accompany presentations.

Unfortunately, the materials that make up this film—dyes (image forming material), plastic/celluloid (film base) and gelatin (binder)—are not chemically stable and will deteriorate over time.

Factors that will accelerate this deterioration are:

• Prolonged or repeated exposure to light. Projectors, light tables and florescent lighting all work to adversely affect the dyes in film.

• Improper storage materials. While notebook pages are a convenient way to store slides, not all plastic sleeving is considered safe and archival. PVC (polyvinyl chloride) is not stable and can emit a damaging acid as it deteriorates. Unfortunately, this material is still being manufactured for the purpose of storing photographs and many collections are currently deteriorating as a result.

• Grouping images by wrapping them with rubber bands or tapes can cause permanent, irreversible damage to slides. Tapes can stain slide mounts and leave an adhesive residue on the film base that is difficult to remove and rubber bands bend and distort both the mount and film.

• Temperature and relative humidity fluctuations. Extreme changes in the environment can be very damaging to slides as they will expand to absorb moisture and then contract when dry. High relative humidity (RH) will also accelerate chemical reactions that cause fading and discoloration.

• Glass mounts vs. plastic/cardboard. Oily residues and fungus can grow in the enclosed environment of a glass mount, and plastic/cardboard mounted slides are vulnerable to mechanical deterioration from fingerprints, abrasion, dust, etc.

• Careless handling. It is very difficult to safely remove fingerprints and other accretions (foreign matter adhered to the film) like dust and dirt. A fingerprint is oil-based and will accumulate dirt that will eventually harden and become very difficult to remove. Although film and emulsion cleaners are available for purchase, they can leave a foggy residue on the film. Wiping a slide in an attempt to eliminate either the fingerprint or the residue can easily scratch the image and cause irreversible damage.

Do you have a question about your image collection? Need assistance choosing appropriate storage materials? Want to learn more about digitizing as a solution to the preservation problem?

Ask the Archivist