The printing-out processing line

Purpose

To take a printed-out sheet from the frame to dry by a sequence whose every bath has a stated job, and to finish holding test results rather than an impression.

When to use it

Every salted-paper, albumen or other printing-out sheet you intend to keep. The exposure and the toning endpoint are judgements; everything after them is a sequence.

The order is not interchangeable. Toning happens before fixing, because the toner leaves silver chloride in the sheet that only the fixer removes.

Before you start

You should already know why a printing-out fixer is weak, brief, plain and alkaline rather than the rapid acid fixer on your shelf, from the salt print chemistry.

Level B. Silver nitrate is on the sheet and in the first wash, under the coating bench sheet: sealed splash goggles, tight nitrile gloves, an apron. Ultraviolet is the other hazard, and it is Part XVI’s enclosure and interlock, or shade, covered arms and eyes off the sheet outdoors.

The absolute rule of this bench: no acid meets the thiocyanate. No acid stop bath, no acid or rapid fixer, no citric clearing bath, no vinegar, no descaler and no acid waste container in the room while the toner is out. The process wants none of them anyway, and the acid exclusion rule governs. The one acid-containing reagent in the session is the residual-thiosulfate test at the very end, after the toner has been bottled and the bench cleared — and that sequencing is a control, not tidiness.

On the bench: the trays laid out and filled in order before the light goes on, because you will be carrying a wet sheet in two gloved hands; a fresh fixer made today; an untoned control sheet; the labelled waste containers.

Procedure

1. Load the frame under the working light: clean glass, negative emulsion down, spacer, the sensitised sheet coated side down, felt pad, hinged back, springs locked. The sheet must be dry, and the frame must not go cold into sunlight.
2. Expose, watching the margin outside the negative rather than the picture, and inspect indoors, away from the printing light, by opening one spring and folding back half the frame.
3. Take it out well past the point where it looks right — about a half to two thirds of the intended final darkness, or when the shadows are just bronzed. Expect two to three stops of overprinting and measure your own.
4. First wash in a tray with changes, not under running water, so that you can see the water. Change it each time it goes milky and keep changing until a trayful stays clear.
5. Stop there. Over-washing at this stage loses image.
6. Bottle that first wash. It is the most concentrated silver solution the session produces.
7. Into the toner wet, straight from the wash, agitating constantly, at the temperature the toner’s own sheet gives. Watch the shadows, where the change starts.
8. Judge by lifting the print, in weak white incandescent light, rather than looking at it lying in the tray. Expect a thiocyanate bath to bleach on entry and then intensify; do not pull it at the bleach.
9. Carry the toning well past the first visible change, and record the immersed time you actually reached.
10. Wash three to five minutes in running water before fixing, because interaction between the fixer and the toner damages the colour and the permanence.
11. Fix by the route you chose and follow it completely: two baths of fresh alkaline thiosulfate with a drain of at least five seconds between them, or the kit’s single weaker bath. Do not exceed the time.
12. Short wash, two to four minutes in running water, to take out the bulk of the thiosulfate before the next bath.
13. Three to four minutes in 1 per cent sodium sulphite with constant agitation, used once and discarded at no more than the published number of prints per litre.
14. Final wash, at least thirty minutes, in a flow that reaches the whole surface and changes the whole volume at least every five minutes. Agitate by hand where more than two prints share a tray.
15. Dry, then flatten while slightly damp.
16. Run the residual tests last, after the toner is bottled and the bench cleared, and read them against the untoned control.
17. Route the streams by the segregation sheet: first wash, intermediate wash, spent toner in its own bottle, spent fixer, washing aid and final wash. Local regulation governs the route, and the disposal caveat says why the course cannot. Check your local regulations.
18. Judge the print the next morning, dry. A print judged wet is judged wrong.

How you know it worked

• The margin bronzed and the print left the frame darker than you wanted it.
• The first wash ended on a clear trayful, not on a clock, and it went into a bottle.
• Toning happened before fixing, and its immersed time is written down.
• The fixing time was short, in a fresh alkaline bath, and nobody lengthened it.
• The wash was a sequence with tests at the end of it.
• No acid was in the room while the toner was out, and the toner’s bottle stands alone.

If a step fails

Step 1, the frame is cold and the sun is bright. Let it equalise. Unequal expansion of paper and negative gives a doubled image at the edges while the centre stays sharp, and an overstressed frame cracks the glass — the glass procedure covers what follows.

Step 3, the print looks right in the frame. It is under-exposed for this process. Put it back: the wet sequence takes several steps of a wedge out of it.

Step 4, the water will not clear. Keep changing it. A cloud that persists is unreacted silver nitrate still leaving the sheet, and carrying it into the toner wastes gold and stains the print.

Step 8, the print bleached and you took it out. That is the thiocyanate’s normal entry behaviour. The sheet is not lost, but its treatment is now shorter than you intended: record the time and use the reserve sheet for the endpoint you wanted.

Step 11, the only fixer to hand is a rapid or acid one. Do not use it. An acid bath attacks the finely divided image silver and liberates sulphur onto it, and with a thiocyanate toner in the room it is also the gas case. Defer the session.

Step 13, the sulphite bath has done more prints than its published capacity. It is a soak, not a washing aid. Discard it and mix fresh, and count the prints rather than the trays.

Step 16, the residual-thiosulfate test shows a yellow-brown tint. Rewash the batch by the full sequence while the prints are still wet and test again. Wet prints are rescuable and dry ones much less so.

What to record

The sheet and its coating record; the light source and the exposure by inspection, with every inspection time; the bronzing observation; the number of first-wash changes and the volume bottled; the toner, its dilution, temperature and the immersed time reached; the fixing route, bath strengths and times; the wash sequence with its temperature; the sulphite bath’s print count; both test results read against the control; and where every stream went.