Archiving Paper Negatives

[bvy]

I've been pinholing for two years now and have a good stack of paper negatives accumulating. And some, I think, are actually worth preserving! As they are now, they're starting to warp slightly. Hopefully they're not too far gone. In any case, I want to do something proper now in terms of indexing and storing them. So I have a couple questions:

1. What's the better method for storing these? I can get the PrintFile clear photo pages which hold two to four 5x7 negatives per page. Or I can get an archival box. (If it matters, this is Ilford RC paper.)

2. It would be good to write a number on the back of my print negatives, so I can match them to an entry in a spreadsheet I keep. At the same time, I want to have the option to contact print at a later date. My current approach is lightly writing in pencil on the back of the paper opposite a very dark part of the image. There has to be a better way.

Thank you!

 

[RalphLambrecht]

What do you mean with 'they're starting to warp slightly'? That doesn't sound good.

Anyway, if you haven't done so already, I would give them a brief treatment of direct-sulphide toning and finish the protection with an image-silver stabilizer (Sistan). Then, store them in archival boxes, separated by archival paper and keep them at a cool dry place away from sunlight. This way, they will last for a long time.

 

[bvy]

Thank you. Warp might be too strong a term. They don't sit perfectly flat. They're starting to curl along the short edge. It's very slight -- for now.

 

[Jon Shiu]

in rc paper the curl is usually due to change in temp and/or humidity.

Jon

 

[Worker 11811]

Could be humidity.

Emulsion swells and shrinks at a different rate than paper as it absorbs or releases moisture.
If emulsion gets drier than than the paper it will shrink, causing the paper to curl toward the emulsion side. (Positive curl.)
If emulsion gets more moisture than the paper, it will expand, causing the paper to curl the other way. (Negative curl.)

To a certain degree, this is normal. Film or paper will always curl, depending on the humidity of its surroundings. If the film curls too much or if you try to force it flat when it doesn't want to, you can damage the emulsion. However, most of the time it doesn't hurt.

Just regulate the humidity of the surroundings where you store your film, negatives or paper. Try to keep it around 50% relative humidity. Limits should be within 40% and 60% with 50% being the average. Over time, the paper should lie nearly flat if it is in the right humidity.

If the case is extreme, you could put the film/paper in a humidity chamber.
Get a plastic container that seals tight. Place a wet sponge in a shallow dish of water. Put your film inside the container, being sure the water can't make direct contact with the film, and seal it up for a day or so. The humid atmosphere in the container will add moisture to the film and allow it to flatten. If the film is too moist, you can do the same thing except use silica gel crystals to absorb excess moisture instead of a wet sponge.