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if you don’t have a cold storage vault, there are a few other options to preserve your slides / negatives, depending on the size of your collection and how much you are willing (or able) to invest.

Digital imaging
Digitally imaging your slides is one way to go. We photograph our slides/negs in RAW, and save them as TIFF files after colour matching them to the original. We use a scanner to create very large files as ‘preservation masters’, then we create smaller ‘access masters’ as well. The preservation masters are stored on a stand alone server with very limited access, to avoid accidental changes to the files.

If you’re working at home, I’d suggest you take high resolution digital images of your slides and save them as TIFFs on a hard drive, and avoid accessing them in case you accidentally change the files. Ideally you should also have a back up hard drive, that you keep somewhere else, in case of fire or theft. It’s useful to have a separate set of the images easily available for quick checks. Digital images are likely to need checking and possibly upgrading every few years, to make sure they can still be ‘read’ by evolving software.

Keep track of your information
You need to link your digital images to the information about the original slide, otherwise you can lose part or all of the image’s meaning. We do this by giving each slide a unique number which is written on the mount, and attached to the digital images. The unique number also attaches to a file where the slide title, place, date and so on are recorded. We have a special museum database for this, but you can use a standard spreadsheet or database.

Freezing
If you want to physically preserve your slides, you can cold-store them in a domestic frost-free freezer, provided they are packed correctly. The United States National Park Service has a great site explaining how to do this:

It’s very important to pack the slides correctly, otherwise moisture can condense on the slides, seriously damaging them. You also need to leave them packed up for a while when you take them out of the freezer, so they don’t warm up too fast. The NPS site explains the whole process very well.

Room temperature storage
If cold storage in a domestic freezer isn’t practical, Keep your slides in a cool, dry area in your house or office. Film materials last best at between 30 and 50 % relative humidity, and the cooler the better. Humidity is quite hard to control without 24/7 air conditioning, but at least you should avoid keeping them in a basement area, or in attics which tend to be either quite hot, or poorly insulated.

Anita