How to store negatives and slides
Negatives are the oddity of a family archive: generally the best-preserved thing in the house and almost never looked at. A strip that has sat in its paper wallet in a cupboard since 1971 is often in better order than every print ever made from it.
Film also fails in its own particular ways, and those are worth learning to spot, because the early stages are the last point at which anything useful can be done.
Four conditions, in order of importance
Cool first. Roughly speaking, every ten degrees warmer halves the life expectancy of colour film — which is why the loft is the worst place in a British house and, inevitably, where most negatives are kept.
Dry second. Below about 50% relative humidity mould cannot get started; above about 65% it will, and a Victorian terrace obliges it.
Dark third, and it is the easy one: a closed box in a cupboard is dark, a shelf beside a window is not.
Steady last but not least. Film copes better with unremarkable conditions that never change than with a daily swing from cold to warm, which is the real argument against both the loft and the garage.
Sleeving, and the one plastic to bin
Polyester, polypropylene and polyethylene are all safe, and are what archival suppliers sell. Plain uncoated paper enclosures are equally sound and cheaper, at the cost of having to take the film out to see it.
PVC is the one to get rid of. Soft, slightly floppy, faintly smelly, common in older negative pages and slide wallets, and given time it gives up plasticiser that welds itself to the film.
Glassine — those semi-translucent wallets from the chemist — was the standard for decades and is not ideal, being acidic and inclined to stick when damp. No cause for alarm, but a wallet that looks or feels damp is worth opening now.
Film that has started to go
A smell of vinegar on opening the box is acetate decomposing, and it accelerates once under way and spreads to its neighbours. Separate the affected strips from the rest and keep them somewhere cooler.
Buckling, channelling and a tacky surface are further stages of the same trouble.
A strong magenta cast means the dyes have faded, which cannot be undone in the film itself although it corrects well in a scan.
Nitrate film, made before about 1950 and often marked along its edge, is genuinely a fire risk as it decomposes. Keep it away from everything else and ask a record office or archive what to do with it.
Scan the negatives, not only the prints
A negative carries more tonal range than any print struck from it, and it has not spent forty years fading on a wall. Where both survive, the negative is usually the better original by a wide margin.
It needs a scanner with a transparency hood, or a bureau service. Worth it for the rolls that matter, not worth it for every roll — which is another way of saying that prints first and negatives afterwards is a perfectly sensible order.
A cool dry cupboard and the right sleeves will keep a family's negatives readable for longer than anyone reading this will require, and neither of them is expensive.
Last checked 2026-08-22