35mm Slide Care

sildesSlide Basics
We’ve all seen 35mm slide presentations. I have vivid (and unsettling) memories of being subjected to one set of neighbors’ inexhaustible numbers of slide carousels full of vacation pictures. If you were invited to a dinner party soon after their winter vacation to the Caribbean, you were sure to see dozens of slides of “our Bruce the Egret,” “another idyllic sunset in Paradise,” and umpteen images of “scallop and conch shells washed up on the pristine beach.” And then there were the slides endured through countless business presentations. (Yawn!) Okay, perhaps I’m not the best audience for a slide show. However, I certainly recognize that those family occasions committed to the 35mm slide medium are of inestimable value to the family. They are a chronicle of life’s events and need to be preserved. 35mm slides were often touted as the more ideal method of developing the 35mm film, because slides were more stable than prints, and you could always have a print made from a slide.

Let’s focus for a moment on what a 35mm slide is, because it is this essence that is the central subject of your care. A slide is actually a piece of 35mm photographic film that was exposed in the camera. One side of the slide is actually an acetate base, while the other side, which possesses the image, is a complex, multi-layered film of gelatin and dyes. Both sides are delicate and slides should therefore be handled with extreme care from the outset. Early slides used a nitrate base, which over time, destabilized and became highly inflammable. Acetate became the more stable base.

The older color slide films have life expectancies of approximately twenty to twenty-five years if they are well cared for. Low heat, low light, low humidity, and vertical storage in a slide mount are essential. There is no ‘best’ 35mm slide film. Kodak, Fujifilm, and a number of others produce exceptional quality film products for use with different lens speeds, for different lighting environments, different ‘graininess,’ as well as color vs. black-and-white types. The professionals always suggest experimentation until you get the look and effect you want.

Mounting and Storage
All that said, the little piece of delicate film needs to be placed in a mounting. The majority of slides have been mounted by default in cardboard mountings. The mounting is like a picture frame. Ideally, the film is not stuck to the mount; rather the mounting material simply holds the piece of film in place by its frame borders. Most of the slide mountings are probably high-quality, safe materials, unless you went a “budget developing route.” (Kodak, Panaflex, Fuji and other names are always trustworthy.)Cardboard slide mounts are always questionable for acid and lignin content. If you re-examine some old slides and see the mounts are yellowing, browning, warping, or the ply is separating, you may want to take action. Companies sell plastic or, better yet, glass slide mounts for the especially important slides you want to preserve. Keep in mind that the film is delicate, and protecting it in a quality mount, and between glass, will prevent scratches, gouges, tears, and will lower contamination risks from other compounds.

Slide carousel trays themselves are plastic and may be a source of contamination. You might want to check on that, but typically the trays are designed of high-quality, high-impact, heat-resistant plastic (or even old bakelite) and will remain stable and relatively neutral. However, a carousel is not where you want to store your slides for extended periods.

When you aren’t taking slides to be presented, they should be stored upright in acid-free containers. I remember the paperboard boxes the slides came in, and the larger cartons in which we lugged the loaded carousels from place to place. They were probably not acid- and lignin-free, and the glue used to hold the carton structure together was probably not of a neutral chemical content. An examination of your collection today and the condition of those paperboard and cardboard boxes will generally show any problems. Discoloration of the cardboard, decomposition, fading of color in the slides, yellowing mountings are all warning signs. However, today there are many storage options for you.

And don’t forget the labeling process! You will want to label your slides, the boxes, the drawers, and other containers with the date, location and subjects’ names.

An Action Plan
The bottom line here is that you should excavate your 35mm slide collection from the closet, basement, or attic, and check its condition. If you are serious about protecting and preserving them, you’ll need to determine the scope of your collection and its problems, decide on what supplies you will need, develop a reasonable budget, and set about the project.

Start by donning a pair of white cotton gloves for handling the slides. Look at individual slides, paying careful attention to the condition of the film and to the mounting material. If the cardboard mounting is yellowing, deteriorating, warped, separating, or otherwise damaged, you need to replace it. Depending on your budget and the scope of your collection’s needs, you may choose from archival quality cardboard mounts, plastic mounts of various types and colors, and glass mounts between which the film can be sandwiched.

Replacing slide mountings should not be a difficult task. With a little training and experience, the right tools, and some patience, you can do all the work yourself. Again, check photographic supply houses and Internet-based archival supply companies for supplies, and don’t overlook volume-pricing discounts for which you might qualify.

Finally, with the mounting work under way, you will want to decide how best to store the slides over the long term. Storage boxes, bins, plastic and polypropylene cases and pocket sleeves, and metal or high quality plastic drawer units are all among your options.

And While You’re Working . . .
Don’t rush headlong through your archival preservation project. Take the time to view share your finished slides with other family members as you go along. Ask for help in identifying people, places and dates, and you may be surprised how many helpers will want to help in various ways. As you watch your skills grow and the collection become more organized, you are sure to rediscover images of people, events, and things you’d completely forgotten. You also may kindle the spark in the next family historian, genealogist or archivist. What a great legacy to give to your family: a well-organized, restored, and preserved visual heritage in 35mm slides. And I personally promise not to yawn through your after-dinner slide show. Just invite me over for coffee and dessert and see.