Stop, fix, wash: the half that decides whether your negatives outlive you

Development makes the picture. Fixing makes it permanent and washing makes it stay that way. People spend years comparing developers and then fix for a guessed minute in tired solution, and the negatives go yellow and faint in a drawer. CineStill's monobath sheet puts the standard in one sentence: for a film to be fully archival, the unexposed silver halide must be fully fixed out and the processing chemicals fully washed away ⁵. Here is how to do both, by the numbers.

First, the handling

All three baths get poured and handled: nitrile gloves, eye protection and ventilation, bottles labelled with contents and date, and the fixer kept apart from everything else because of where it has to go afterwards.

Stop

A stop bath is a weak acid that halts development at once and keeps developer out of the fixer. Ilford's HP5 Plus sheet says a plain water rinse can be used but recommends an acid stop such as Ilfostop, which also carries an indicator dye that changes colour when it is spent ². The time is short: Ilford's HP5 Plus sheet gives Ilfostop at 1+19 for 10 seconds at 20 °C, usable from 18 to 24 °C, with a capacity of 15 rolls per litre ², and Kodak's Tri-X sequence gives its Indicator Stop Bath 30 seconds ³. Two cautions. Pour the developer out fully before the stop goes in, and never let stop or fixer splash into the developer bottle; Ilford warns that contamination that way leads to inconsistent results at best ⁴.

Fix

Ilford Rapid Fixer is an ammonium thiosulphate fixer. It contains no sodium thiosulphate, the "hypo" of the old formulas, and Ilford says it must not be used with a fix hardener ¹. For film it is diluted 1+4; for paper, 1+4 or 1+9 ¹. Ilford's minimum times at 20 °C with fresh fixer are 2 to 5 minutes for general-purpose film, the range covering different film types; RC paper takes 30 seconds at 1+4 or 1 minute at 1+9, fibre paper 1 minute at 1+4 or 2 minutes at 1+9 ¹. Agitate film in the fixer as in the developer, four inversions in the first ten seconds of each minute ¹.

Ilford's sheet describes the clearing test: put a drop of fixer on a scrap of unprocessed film, wait for a clear spot to form, then immerse the scrap and time how long the rest takes to clear to match it. The fixing time needed is double that clearing time, and the fixer should be discarded when the clearing time in used fixer exceeds twice the clearing time in fresh fixer ¹. Ilford gives the capacity as 24 rolls of 135-36 per litre of 1+4 working solution, 80 sheets of 8x10 RC paper at 1+4, 40 sheets of fibre ¹. Write the count on the bottle. Those are working capacities. For fibre prints that must last, Ilford sets a stricter limit on the silver the fixer may carry: below 2 g per litre where a high level of permanence is required, and no more than 0.5 g per litre for long-term storage, which means far fewer sheets per litre or a two-bath fixing routine ¹.

Keep every solution within 5 °C of the developer temperature; Ilford puts that rule at the top of its fixing instructions ¹. A warm fixer after a cold developer can reticulate the emulsion into a fine crazed pattern that no scanner setting will remove.

Wash

Washing removes the thiosulphate and the silver complexes the fixer holds, and if it is skimped the image slowly sulphides. Ilford's tank method is the one to learn, because it is quicker than running water and uses far less of it: after fixing, fill the tank with water at the same temperature as the solutions, invert it five times and drain; refill and invert ten times; refill and invert twenty times ². The alternative in the same sheet is 5 to 10 minutes in running water ².

Kodak's sequence for Tri-X is longer by default: 20 to 30 minutes in running water, or a 30-second rinse, 1 to 2 minutes in Hypo Clearing Agent and then 5 minutes of washing ³. The hypo clearing bath is the trick behind the short time: it helps the retained fixer leave the emulsion, so the wash that follows can be short. For paper, Ilford says RC prints wash in 2 minutes in running water above 5 °C, and 30 seconds of vigorous washing will do when speed matters more than permanence ¹. Fibre paper is another matter and has its own guide in printing.

The last bath and the dry

A wetting agent stops water drying in drops that leave marks. Kodak gives Photo-Flo 30 seconds as the final step, at the dilution printed on the bottle ³; Ilford says start Ilfotol at 5 ml per litre, 1+200, and adjust for your water, because too much leaves marks as surely as too little ². Hang the film with a clip at the bottom, do not squeegee, and dry somewhere nobody walks. A steamy bathroom after a hot shower is the classic dust-free drying cabinet.

Sleeves, boxes, decades

Dry, cut into strips of six, sleeve in archival polyethylene or paper pages, and store cool and dry. The CineStill sheet's two requirements are the processing ones ⁵; storage is the rest of it, and a damp garage undoes both. Done properly, the negatives from your first roll should still be readable when the scanner that read them is long gone.

Disposal

Spent fixer carries silver. Many municipalities ask for it to be collected rather than poured; some labs and camera shops take it for silver recovery. For developer and stop, follow the product's own instructions and your local waste rules; some places allow small volumes down the drain with plenty of water and others do not. Never mix used baths together in one jug: the fixer's acidity and the developer's alkalinity do not need to meet in your sink.