Fun with salted paper

Well, I've finally settled on an alternative process to try, and I've decided to begin playing with salted paper. I picked up some silver nitrate from B&H when I was there last night, and I have some chemical grade sodium chloride.

I mixed up a 10% silver nitrate solution, and a 3%-ish salt solution, and coated them onto paper when I got home.
The paper, which is some drawing paper that I had, is obviously an issue, as it darkened to a light tan as the silver nitrate coat dried, and curled when it got wet.

I did, however, get some results. I printed a high contrast negative from the computer, on transparency film, and exposed it and the paper under a fluorescent light (which is the best thing i had at the moment) for about 25 minutes. I didn't fix the print.

The result was a very nice dark brown, though the image was underexposed, and quite in contrast. The underexposure, I'm sure, contributed to this.

I'm going to pick up some paper tomorrow, and hopefully get a successful print in the sun.

Now just to find a suitable paper ...

Congratulations!

Look around for some nice watercolor paper. Most of the brands will work, but I've had the best luck with Crane's Diploma Parchment.

If you can work during daylight hours, the sun is a great UV source. You knew this of course... Otherwise get your hands on some BLB flourescent bulbs. Spiral with Edison base or short tubes. Very easy evening project to build an exposure box.

If you don't have good negatives at hand, you can make photograms as a way to test your paper and exposure times.

I'll try photograms; that should be easier. I'm sure I'll get some better images. I'm also hoping that the exposure times in the sun will be shorter.

I'm a poor college student at the moment, but I'm saving up for some BLB tubes, and the requisite ballasts and fixtures.

I ordered some spiral BLB bulbs at a reasonable price, blacklight.com I think it was. Then used four of the "cheap" ceramic Edison bases and lamp cord. Whole thing plugs into a power strip so that gives me a switch and its own breaker.

Built a box and painted the whole thing white inside and out. This worked out great for up to 8x10s but the open end of the box is my limiting factor for size. I could make larger prints but to do this I had to hang the box upside down, over the contact frame. Since the intensity falls off as 1/d^2 the exposures increased a lot once I got it far enough up to cast even light over the area.

So now I need to build a bigger box. This time I think I'll go with the 24" tubes and the inexpensive pre-wired fixtures.

One other tip, turn on the lights for a few minutes prior to using them. I've noticed one of my bulbs doesn't start up (at least in the visible spectrum) as brightly. Yes I know you aren't supposed to look at them but I did. After 3 or 4 minutes I glanced again and couldn't tell a difference (again visible spectrum). So I turn them on for 5 mintues before starting a session. If you suspect a problem with balance of intensity, just rotate your frame 1/4 turn 4 times during the exposure.

In reading over the book "Coming Into Focus," a great alt process guide, there is mention that the BLB tubes put out much less UV than the BL, and are more expensive to boot.

- Justin

Thanks for pointing that out, Justing; I just re-read my post and realized that that's what I meant to say.

Out of curiosity, does anyone know if the UV germicidal bulbs (the clear ones) will work?

If you are going to make successful salt prints, you need to get as close to the methods of the 1840's as possible. These were made on extremely thin paper which was gelatin sized. After several years with this process I have settled on the following basics.

Start with a 100% cotton writing paper. Water color paper is too heavy and does not work well with salting process.
Make up a salting solution containing 12% NaCl and 2% unflavored gelatin.
After drying, coat with a 12% solution of AgNO3.
Expose under a negative to UV source.
Wash out for 5-10 minutes and then use Clerc's gold toner.
Fix in a very dilute solution of sodium thiosulfate (hypo). Rapid fixers bleach the image too much.
Wash well and dry face up on screens.

This is basically the process I used to print an 1840's paper negative for the Museum of Photographic Art.

Jim Noel said:

... 12% NaCl and 2% unflavored gelatin.
...

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Jim,

Is this correct or a typo? Everything I've ever read about the process calls for between 1-2% salt content and as you state, silver nitrate around 12%. Isn't silver nitrate supposed to be present in great excess in the process?

Can you post some examples from this recipe?

I've seen the statements about BLB vs BL but there really isn't THAT much difference in the wavelengths that "matter". BLBs seem (at least in the USA) to be easier to source than BL. YMMV

Anyway, BLB will work but of course Mr. Sun is still your best bet!

I'll agree with rwyoung; the BLB bulbs are definitely easy to find, at least compared to BL stuff.

I know that Mr.Sun's the best bet, but he seems to be rather shy during New England winters.

Is there any issue, aside from long exposure times, with printing outside on an overcast day?

Not really any problem on overcast days. I've seen it suggested that you point the frame 180 degrees from the sun at open-sky to increase contrast. But on an overcast day I bet it doesn't make a difference.

Keep it pointed at the sun and if your exposure is long, you might want to move it a bit.

htmlguru4242 said:

Thanks for pointing that out, Justing; I just re-read my post and realized that that's what I meant to say.

Out of curiosity, does anyone know if the UV germicidal bulbs (the clear ones) will work?

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I would take care with those -- they probably put out a lot of the UV-type ("C"?) which is very damaging to eyes and skin.

Vaughn

PS...did some quick research...Germicidal bulbs work at 253.7 nanometers (UVC) -- too short for exposing alt materials (but not too damaging to eyes and skin, but will cause sunburns). UVB (280 to 320 nanometers) can expose alt materials, but is easily filtered out by glass -- and can cause skin cancer and cataracts. UVA (BL and BLB bulbs, etc...320 to 400 nm) is what we want.