Photo Preservation

How to preserve your slides and photos

Glass Slides

The very early photographic slides were known as glass lantern slides. They consisted of a positive black and white image sandwiched between two pieces of glass with a paper mount. Paper tape was usually used to keep the pieces of glass together and each slide measured 3 1/4 x 4 inches. Hand coloring was sometimes used prior to the early color process which was known as Autochrome. This became available around the early part of the 19th century. These lantern slides remained popular from 1850 to 1950.

If you have glass slides which are in good condition with intact glass and tape seal, then they should be relatively stable. Cracked or broken glass or missing tape causes the image to be exposed to moisture, dirt, and pollutants.

It is possible to fix some of this damage yourself using replacement glass of the same size and thickness. Broken tape must be replaced using tape which is safe for photographs. Do not use duct tape, masking tape or cellophane tape to hold the slide together, as these contain adhesives which can damage your photographs.

If there is any damage to the original image, it may be possible to repair the damage, but you will need to contact an expert in photo restoration. Do not attempt to clean the image yourself. You will destroy it.

Glass slides need to be stored vertically with support between every few slides. Make sure the storage box is strong enough to support the weight of the slides.

Film Slides

Initially Kodak lacked a method for mounting the images after processing, so they sent them to their customers so that they could be glass mounted at home. Plastic and cardboard film slides became available when Kodak introduced Kodachrome film in 1936.

There are pros and cons to each type of slide mount. Glass protects images from abrasion but is heavy. Cardboard is cheap but acidic while plastic is sturdy but gives off gases that can deteriorate the pictures. Even though plastic and cardboard aren't preservation quality materials, improper handling and environmental factors cause more damage than poor quality mounts.

Storing Slides

Store your slides in a dark place with a stable temperature and humidity. Handle by the edges only to prevent scratches and fingerprints.

Limit the projection time. Heat and light fades the images. Both glass and film slides are one of a kind images and irreplaceable. It's better to project copies of your favorite slides than the originals.

Store your slides in polypropylene pages or storage boxes if possible. Other types of plastics tend to deteriorate with time especially the soft plastic of slide pages.

Copying Slides and Photographs

It used to be costly to make a print from a slide. Now, thanks to digital scanning equipment, copying photographs is cheap and easy. It is now possible to make copies of slides using the a slide attachment that comes with some scanners, but if you have a lot of slides to convert to digital format consider investing in a slide scanner. There are a wide variety of slide scanners on the market.