Save the photos: Recommendations for optimal preservation

Spend time talking photo preservation with Bob Herskovitz and Joe Hoover of the Minnesota Historical Society, and you may find yourself thinking about the contents of your closets.

All those pictures of your kids or grandkids that you plan to file in albums — er, as soon as you have some time. Those yellowing Kodachromes and Polaroids from your own childhood, stashed in binders with sticky plastic pages before anyone had heard the term "archival quality." Those snapshot-packed shoe boxes, those plastic bins you bought at an after-Christmas sale — now you know they're containers that can leach gases or acids that — yikes! — could be eating away even now at those smiling images.

Relax. Herskovitz and Hoover, the Historical Society's outreach conservator and digital technology outreach specialist, respectively, certainly have high professional standards for preserving data. But luckily, they also have a way of reassuring.

"If you're saving things, that's good," Herskovitz said. "If you're being careful how you're saving them, that's better. If you're using archival materials and good storage environment, that's best."

So perfection isn't required (and archival supplies can be expensive). But the more closely you follow best practices, the more likely your photos will last so that you, and maybe your great-grandchildren, can enjoy them in the future. Here are Herskovitz's and Hoover's recommendations for optimal preservation.

Store flat, either vertically or horizontally, inside acid-free paper or plastic sleeves labeled safe for archival photo storage (note: those supplied by the photo processor may not qualify). Make sure any plastic is free of polyvinyl chloride (PVC), which emits damaging gases. If using boxes, again make sure they're archival quality — that is, neither acidic cardboard nor gas-emitting plastic.

Store them in an environment that is cool (which eliminates most attics), dry (which eliminates most basements) and dark (which can come from a closed drawer or box.) Don't store them near a water pipe or anything else with the potential to leak.

Again, store them in a cool, dry, dark place — though ideally not the same place where you keep your negatives, in case of fire or other disaster.

Place photos on walls with the least light exposure (next to windows is best; across from windows worst). Keep draperies closed when possible, turn off lights when nobody's in the room (yes, even artificial light is damaging over time). Or display a copy of the photo, safely storing the original.

Frames are generally safe, Herskovitz said, but avoid letting a photo press against glass, because the coating can soften and stick. Create a space between the print and the frame by using either a mat or a polypropylene strip called a spacer (available at frame shops or online) that runs along the inside edge of the print.

Don't apply any form of adhesive to the print, even on the back, because it can stain through. The best way to secure a print in a frame is with photo corners or photo strips that hold the edges in place.

If possible, use pencil, which doesn't fade or bleed. Newer photos with slick coating may require ink, but preferably a pen labeled for archival use. Write along the edges on the back of the print, not in the middle of the image; Herskovitz has seen old photos with ink that "has sort of migrated through" from the back and is visible in front. He does not recommend self-stick labels unless affixed to a sleeve or container.

You might think the latest technology would best preserve images, but in fact it's the other way around. "Those photo prints, if they're correctly preserved, they're going to last 100 years, if not 500 years," Hoover said.

In contrast, newer media, such as magnetic tape, are more ephemeral, and the equipment for running them is constantly being upgraded or slipping into obsolescence. Consider what's happened to cassette tapes, VHS videos and floppy disks, and realize that flash drives, memory sticks, CDs and DVDs will eventually meet the same fate.

"There's no way that you will be able to look at a digital image produced today on the technology that will be available in 100 years, or probably 50 or 25, or maybe even 15," Herskovitz said.

Still, we're storing more and more of our memories on digital devices, because they make our photos and videos easy to capture, to view, to edit, to share, to post online, to slip into a pocket or purse. So what's the best way to preserve them?

Ideally, store digital images in at least two places: a physical place and a virtual place. "Just making two copies, and having one away from the other one, that's a simple thing to do," Hoover said.

"Never rely on just having it on the cloud — have a hard drive backup," Hoover said. "But never rely on just a hard drive backup. The dog could pee on your hard drive, or chew on it, which happened to me, or it could be lost in a fire, or it could freeze."

What fancy gadgets will we, or our descendants, use to store and view photographs and videos? Good luck predicting. British researchers recently devised a way to encode texts, photos and audio files and store them on strands of synthetic DNA. They say the technology could be available to consumers within 10 years. Who knows — maybe eventually we'll just have them implanted directly into our brains.

But you might not want to wait until then to do something about those closets.