The gold toner that did nothing because the first wash was omitted

Owned by Break/Fix — the printed-out image that faded, whose fifth case names this entry and opens with Reilly’s list of eleven factors that influence a toning result, of which four account for nearly every dead bath: free silver carried in from an omitted first wash, a bath at the wrong pH, a bath simply spent, and a trace of fixer. It adds the two failures that look like a dead toner and are not — a thiocyanate bath bleaches before it intensifies, and an un-neutralised gold(III) bath gives a flat, lifeless, reddish image. Gold toning and the permanence of printed-out silver owns the chemistry. This entry was written earlier from the encyclopaedia and the formulary.

What you see

A print that went into the gold bath and came out the same colour. No shift towards blue or purple, no change in the shadows, and after several minutes of watching, nothing. On an expensive bath that is an alarming experience, and the usual first conclusion — that the gold is spent — is often wrong.

Likely causes

1. The pre-toning rinse was omitted. Bostick & Sullivan’s step 6 is a two-to-three-minute rinse in gently running water, and its stated purpose is twofold: to remove the excess silver and to prepare the surface to evenly absorb the toner.
2. The bath really is spent. They put a figure on it: each print uses up approximately 5 ml of gold chloride solution, and the remedy is either 5 ml of the gold stock after every print or 25 ml when toning slows to an impractical speed.
3. A dry print, not soaked. Kodak’s general instruction for toning is that a print already dry should be soaked in water for two to three minutes first.
4. The print was fixed first. On these processes toning normally comes before fixing, and a fixed print has had the silver the toner was supposed to reach converted and removed.

What is happening: the chemistry and physics

Toning is a reaction with the image silver, so the toner has to reach it and has to have something left to react with. Both halves fail in the ordinary way this fault occurs.

What the rinse removes is a competitor. Bostick & Sullivan describe what happens in it: the print lightens a shade or two and shifts towards red as the excess silver reacts with the chlorine in the tap water, forming a purple mist which floats off the paper. That excess silver is unreduced sensitiser sitting in the sheet. Put it into a gold bath instead and it is in contact with the gold solution — and gold(III) is a strong oxidant against silver.

The course states the consequence carefully. Bostick & Sullivan give the rinse’s purpose as removing excess silver and preparing the surface to absorb the toner evenly; they do not state, and this course will not assert as measured chemistry, that the excess silver consumes the gold stoichiometrically. What is sourced is that the rinse is a required step with a stated purpose, that its omission leaves free silver in the sheet, and that the same manufacturer meters the bath’s life in millilitres of gold per print — so a bath asked to deal with free silver as well as with an image is a bath being spent faster than the arithmetic allows.

And the surface half is real too. A toner that cannot penetrate evenly does not tone evenly, which is why the same instruction covers both. Bostick & Sullivan note that POP has a thick gelatin emulsion and it takes time for the toner to work through to the silver, while prints without gelatin — Van Dyke, kallitype — tone much faster. A dry, unsoaked gelatin layer is the slowest case of all.

!The confirming test: a fresh strip and a rinsed strip

Two strips, one bath, one variable.

Cut two identical exposed prints. Rinse one for the full two to three minutes; put the other in unrinsed. Tone them together in the same bath.

• The rinsed strip tones and the unrinsed one does not: the rinse was the fault, and the bath is alive.
• Neither tones: the bath is spent, or was never made up correctly. Add gold and repeat.

Then check the bath itself. Bostick & Sullivan describe what a correctly mixed bath does: the gold often momentarily turns brown or orange when first mixed and should quickly redissolve. A bath that stays cloudy or keeps a precipitate was not made up right.

And do not judge too early. They add the observation that on some types of print the toning will be faint until the print is fully dried — so a strip that looks untoned wet may not be.

Diagnostic questions

• Was the print rinsed before toning, and for how long? Two to three minutes in gently running water.
• Did you see the purple mist? It is the visible sign that the rinse is doing its job.
• How many prints has this litre toned, and has it been replenished? About 5 ml of gold per print, on the supplier’s own figure.
• Was the print dry? Then it needed a soak.
• Which process, and in what order? POP is toned then fixed; kallitype, Van Dyke, salt and albumen follow their own rinsing and clearing and are not fixed before toning.
• What is the tray made of? Kodak: not metal. A metal tray is a competing reducing surface for a noble-metal bath.

Corrective action

Rinse and re-tone. A print that has not been fixed can go back through the sequence, and this is the one fault in the toning family that is usually recoverable.

Replenish the bath if the fresh-strip test says it is spent, using the supplier’s own arithmetic rather than adding gold until something happens.

Do not extend the toning time to compensate. On a resin-coated support that is how you get toner penetration at the edges, and on any print it is how you get uneven toning.

Prevention

Treat the rinse as a step, not a courtesy. It is numbered in the instructions for a reason.

Dissolve the fixer properly too, while you are being careful: Bostick & Sullivan warn that even very small crystals will cause stains and unevenness when they settle on your print.

Meter the gold. Add 5 ml after each print, or 25 ml when the bath slows, and write down which you did.

Keep the order of operations written on the wall, because it differs between the processes that share this toner.