Could Color Transparency Film Housed in Plastic Sleeving Be Negatively Effected Over Time?

At the same time, airflow ensures a fresh supply of mold spores, insects etc. If you package the slides in an airtight container under low humidity (not abnormally low; just not enormously humid), and ensure tempersture remains fairly constant,
they will keep perfectly fine.

What I'm saying is that it always ends up being about storage conditions and especially the prevention of moisture getting to your slides. This is the main parameter to control. Ventilation is of secondary importance and mostly relevant if storage conditions are suboptimal to begin with; it's a bit of a band aid to make the 'best' out of poor storage conditions such as in attics and basements...

Exactly - storage conditions. Note that spores are everywhere no matter the air humidity and place where you live. Everywhere. You breathe in stupid amounts of the stuff, your immune system handles it and doesn't provide it with conditions suitable for it to grow, so it doesn't. Dry air too - not great if you're the omnipresent spore. Humid places? Sure, mold can grow now! Therefore it's about the second variable we can somewhat influence: storage conditions and what you can do about it with equipment you have, starting from the rationale of:
1) practicality or solution not getting in the way of user experience
2) cheapest/most straight-forward option out there.

In practical terms I'd encourage to compare these two options - what's more feasible:
1) airtight container of sufficient volume and practicality - how can one achieve stable temps/humidity in moderate climate? Inner condensation exists too! You'd have to disinfect the box each time you open in if your main goal is to protect your slides from the omnipresent spores - gets impractical very fast and idea is unfeasible to begin with.
2) simple movement of air against development of suitable environment for mold to thrive: simple passive ventilation. You could even add some anti-fungal agent to your rinse aid and forget about it for longer.


I'd say that my living/storage conditions are those of the extremes, so my household serves as fairly good stress-test:
- house built on a reclaimed bog: humidity is very high all-year around
- house is poorly insulated: temps fluctuate from ~15C to 33C
- no AC, no climate control
- heated via local heating: a wood furnace heats up a boiler that sends heat throughout the pipes/radiators. Air dries very quickly when house is heated, temps increase rapidly.

That simple box is sufficient against mold in my extreme conditions for 10+ years now. Problems arising only in AN glass mounts, kept inside these storage boxes.

So I ask - why complicate stuff? Let the air move and collect the moisture so that a suitable environment for mold doesn't occur in the first place.

Ivo Stunga said:

In practical terms I'd encourage to compare these two options - what's more feasible:

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Either will end in disaster if conditions are suboptimal. See my experience with hundreds of affected slides.

Ivo Stunga said:

That simple box is sufficient against mold in my extreme conditions.

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You don't know. The affected slides we have in our family archive started to show signs of deterioration after a decade or more. Our family archive goes back to the early 1960s with B&W materials (with a few items preceding this down into the 1930s) and color slides starting at around 1968. We have a few thousand color slides in this archive, spanning the decades up to the early 1990s, then a hiatus (color negative film in that ear), and then around 500 to 1000 more from the 2000-2010 period. The latter have been stored at least in part under atrocious conditions, but are (seemingly) fine. Experience tells me not all of them will still be fine 10 years down the line.

Anyway, don't take my word for it. Find out for yourself.
At least you have the advantage that you appear to have been using mostly modern slide film, which fares better even under adverse condition than the stuff from the 1970s and early 1980s.

koraks said:

At least you have the advantage that you appear to have been using mostly modern slide film

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True. Oldest film I've shot was Sensia or Astia.

koraks said:

You don't know.

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Could be. Projection/inspection once in 2-3 years with 50x magnification, however, tells all there is to tell: if mold present, it's easy to spot and stop the process by treating/rinsing it with isopropyl alcohol and/or anti-fungal agent (haven't done that yet).

Ivo Stunga said:

Projection/inspection once in 2-3 years with 50x magnification, however, tells all there is to tell

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Maybe. Maybe not.
How well your discipline of periodic inspection will stand the test of time, we can only guess for now.

When given the choice, I'd opt for passive security over active security any time. But maybe you're not as lazy and undisciplined as I am.

I'm plenty lazy therefore I opt for periodic observation and dealing with problem if it occurs : D
Me loving some slide show - inspection and revisiting of earlier slides is not a problem - both AN and free mounts. Those beauties aren't meant to sit in the dark forgotten : )
The exposure to projection heat/UV/Vis-light (incandescent bulb after all) could also be one of the reasons I don't observe mold on my slides as much.

So I keep observing.
And I like the anti-fungal agent idea, could incorporate it in my workflow as a preventative measure. Has anybody done it?

Ivo Stunga said:

Any flow of air/gas helps against accumulation of moisture/mold - hence the vents of said slide storage boxes, no? Hence mold on slides/negatives in sleeves, hence mold on slides sandwiched in AN glass mounts where the airflow is nonexistent. And zero mold on open-framed slides, all other conditions being equal.

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Even when I would remount slides in glass so that I could crop the slide, I made sure that neither side of the slide was mounted to touch the glass. The OP's problem has never been mine for slides or prints.

There are archival products available for dealing with excess humidity in order to prevent the growth of microbes. Silica gel packets, sheets, sachets and so on. Some of them can be reactivated and reused when they become too saturated to be effective. I suspect that this would be preferable to having a constant flow of mold and fungus spores cycled through in air with suboptimal humidity. You can dead reckon the amount of moisture that will ingress into the box based on predicted weather conditions and the shape of the box and use that figure to determine what mass of silica gel is necessary to keep the film under optimal conditions for x amount of time then reactivate or replace the silica gel every half that time.

_T_ said:

There are archival products available for dealing with excess humidity in order to prevent the growth of microbes. Silica gel packets, sheets, sachets and so on. Some of them can be reactivated and reused when they become too saturated to be effective. I suspect that this would be preferable to having a constant flow of mold and fungus spores cycled through in air with suboptimal humidity. You can dead reckon the amount of moisture that will ingress into the box based on predicted weather conditions and the shape of the box and use that figure to determine what mass of silica gel is necessary to keep the film under optimal conditions for x amount of time then reactivate or replace the silica gel every half that time.

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Agreed. The point, surely, is that you have to actively curate a collection of transparencies. You can’t rely on their being in archival wallets while you get on with the necessities of life. You even have to actively manage silica gel.

Silica gel between trays wouldn't hurt indeed - the question would then be how often would one need to microwave/oven some packs to remove moisture from it/restart it?

Ivo Stunga said:

Silica gel between trays wouldn't hurt indeed - the question would then be how often would one need to microwave/oven some packs to remove moisture from it/restart it?

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Pretty often under conditions such as a typical attic or basement. I frankly don't see much added value to it.

koraks said:

Pretty often under conditions such as a typical attic or basement. I frankly don't see much added value to it.

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There is only any point if the photos are in an air-tight container, i.e. if the total amount of moisture to be removed is small and not renewed. Every time you open the container you go back to square one.

There is a type of silica gel containing a colored indicator dye telling you when it needs to be baked out again. Or there are other methods of keeping humidity low in storage spaces, like Dri-Out canisters, which are more practical than silica gel, but likewise need periodic recharging. Museum collections need much more active humidity control, which can get expensive. This is an important topic not only with respect to film and slides, but lenses and cameras too. You don't want condensation or mold growth on any of them. Same goes for prints. And heaven help you if you live in a humid tropical climate.

With black and white film, people talk about the risk of vinegar syndrome deterioration with emulsions coated on an acetate support. You also hear it said that having such film stored in plastic sleeves or other ways where air cannot easily circulate exacerbates the vinegar syndrome. Some authorities suggest storing in archival paper containers instead. Some slide film is on an acetate support. A number of sources say that cooler storage is better. In the context of cinema film, a blogger says that a 1000 ft roll of exposed film over its lifetime will release the equivalent of 250 teaspoons of household vinegar. Still film obviously will release a lot less, but still considerable.

My slides are stored in archival paper boxes that fit in plastic file folder boxes purchased from office supply stores. These boxes are not air tight but close to it. There is a silica gel canister in each box that is renewed twice a year.

Negatives and unmounted transparencies are in polyester sleeves called "fold lock" but with the flap cut off and then the sleeves are inserted in polyester pages. And they too are stored in plastic file folder boxes. Circulation is zero but the humidity is kept very low with the silica gel canisters.

My house (in the southern USA) is pretty dry in the winter from heat and summer from the air conditioning but the humidity in the spring and fall can get too high- that is when the silica gel canisters are renewed.
I have had no problems with mold in over 30 years.

DF said:

I'm wondering if color transparency film housed in cardboard mounts would be in a sense healthier because of the space enabled, whereas in plastic sleeving, whether it be in roll form direct from processing or in, say, a PrintFile page, could cause problems over time due to the direct contact between the film and the clear plastic. Yah, I'm sure excessive humidity would create sticking for one example, but any other kind of damage?

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Can't speak to transparency film but my color and B&W negatives have been stored in Print File sleeves for up to 40 years and suffered absolutely no damage at all, stored dry at room temperature.

Anecdotal evidence, Ralph. There are also people out there who could tell you stories about ruined negatives. It all depends; and humidity/climate is an important variable. Also keep in mind that most older b&w films were nowhere near as slick as many current ones.

'Haven't heard that much about dessicant packets, for 'added' protection, placed in whatever storage apparatus one prefers.
Anyone ever tried Zorb-It?

There were several posts already mentioning desiccants. Numerous brands are available, some in ordinary hardware stores.