I got my enlarger and I'm ready to start making prints.

For chemicals, I have Kodak Dektol Developer and Fixer; however, I'm missing Stop Bath. I've heard conflicting reports about how necessary Stop Bath is.

I've been told by some people that just a good rinsing will suffice and others say that your prints will continue (forever) to develop without it.

What has been your experience? Will my prints disintegrate without Stop Bath?

  • Been ages since I've done any development. I'm pretty sure you could substitute vinegar, and I think the fixer is acidic enough to stop development, but it will deplete the fixer much faster. I know in the same situation I rinsed the prints with water and put straight into the fixer, and IIRC short-term it certainly seemed to work, but I couldn't say if the prints didn't then deteriorate over time. Short-term you could try skipping it, but long-term I would use it. Was always cheap and lasts forever, no point IMO to skip.
    – MikeW
    Apr 14, 2015 at 3:29

4 Answers 4


Conventional wisdom says yes, you should use a stop bath. The stop bath is a very weak acid (similar to white (distilled) vinegar) and is used to neutralise the developing agent. This guarantees two things:

  • You can be sure that you won't have any additional development happening after the developer bath.
  • You won't contaminate your fix with developing agent.

Personally I've never used a stop bath - I was taught just to rinse under cold running water for several minutes. If you're using still water and agitating, frequent changes of the water in the bath is recommended. Without using a stop bath I may be getting a slow/small amount of developing happening in the print during my water rinse until all of the developer is washed off, and this is a problem that you would not have if you use a stop bath. Another plus for using stop baths is that the chemicals are very cheap. If you have a spare tray and desk space is not really worth skipping. Note that this is using RC paper. If you're using fiber based paper I would definitely recommend a stop bath as the paper absorbs developer and rinsing it isn't going to be enough to confidently arrest development.

I've checked [1][2] and [3] for references to stop bath and it's only the Ilford Manual of Photography that goes into any detail. Although this is describing film development, the same applies:

A plain rinse bath is very commonly employed betweeen development and fixation to slow the process of development, by removing all the developing solution merely clinging to the surface of the film. A rinse bath does not completely stop development - because it leaves more-or-less unchanged the developer actually in the swollen emulsion layer - but it does remove much of the gross contamination of the film by the developing solution.


The rinse bath then serves not only to slow development, but to lessen the work that has to be done by the acid in such a fixing bath. Rinsing then "protects" the fixing bath.


Although a plain rinse bath is all that is commonly used between development and fixation, a better technique is to use an acid stop bath, the function of which is not only to remove the developer clinging to the surface of the film, but also to neutralize developer carried over in the emulsion layer, and thus to stop - not merely slow - development.

I hope that helps. I haven't had any noticeable problems in prints using RC paper and washing for several minutes in running water or agitated water in a bath, but YMMV. Considering the price of the chemicals and the very small amount of extra work, I would definitely use an acid stop if I was going to make a print for somebody other than my own wall.

others say that your prints will continue (forever) to develop without it.

When you expose the silver halides in the emulsion/paper to light you produce a latent image on the medium. As well as doing other things like softening the emulsion in film, activating the developing agent, and also restraining the developing agent in the case of potassium bromide, the alkaline developing solution combines with oxygen to reduce the silver salts that have been exposed into actual metallic silver. The stop bath introduces an acidic environment which neutralises the developer, and as discussed earlier not an absolute necessity. The reason for this comes from the fixer. The fixing solution includes chemicals such as sodium thiosulfate which takes the un-reduced silver halides (i.e. anything that wasn't exposed to light) and makes them water soluble. This is why fixing is absolutely necessary. After sufficient fixing there will be no more light sensitive halides at all on the film/paper. To answer the question above, assuming you have properly fixed your print they will not continue to develop, regardless of whether you used an acid stop bath or a water rinse. There's simply no more light-responsive chemicals around to develop. This doesn't mean the stop bath is unnecessary though for the aforementioned reasons. If you improperly fix your print you will start to see orange/brown stains developing in the paper. For an example of what to look for in an improperly fixed print just leave an undeveloped sheet of paper out of the box for a few hours.

[1] The Darkroom Handbook, second edition, 1984, Michael Langford, Ebury Press

[2] The Master Printer's Workbook, 2003, Steve Macleod, Rotovision

[3] The Manual of Photography (formerly the Ilford Manual of Photography), sixth edition, 1972, Focal Press

  • I'm sure I used to just use a tray of water as the stop bath, perhaps even with a drop of rinse aid in it to reduce the surface tension and help stop drops sticking to the print when moving to the fix, but it was quite a few years ago now since I've done it Apr 14, 2015 at 10:21

Martin Foot's answer is a very good one. However there are a couple of things from my experience that I could add.

I've been told by some people that just a good rinsing will suffice and others say that your prints will continue (forever) to develop without it.

Yes, rinse with cold (running) water is enough. Cold water will stop the development process equally well like a stop bath. It will certainly not continue to develop forever. And it has other advantages:

  1. you can put a print back into the developer if you changed your mind. You'd kill the developer with a stop bath contaminated print.
  2. you wont contaminate the fixer with stop bath. This is usually not a big problem but if you want to keep the fixer for a long time it will
  3. you will not have the vinegar smell in your working room. (see below)

In my carreer I have seen a number of laboratoiries. There is actually only a single reason why there is a stop bath in the first place:

The lazyness of the casual photographer (see the answer of aussiegeek)

Since photographers are usually lazy and don't care too much about cleanliness, the industry has invented the stop bath. It's something more they can sell and it makes the process more successfull for the average (lazy) photographer.

The first rule in your "photographic laboratory" should be: keep it clean. And "clean like in a kitchen" is not good enough. You should, whenever you think that your hands may have become contaminated with chemicals, walk over to the tap and wash! Do the same with all the equipment. Work as if all the chemicals are deadly poison - it is not - but that's the care you should take.

Don't underestimate the third point above. Your stop bath will be the item in your room that you smell even from the outside. If you work in this room for hours the smell can become mind-numbing. Some people are allergic to vinegar. Some photographers have become allergic to vinegar because of "overdoses" in the laboratory.

Care for your equipment is another point. You have your enlarger standing in the same room where your chemicals are. The vapors of the chemicals will have an effect on your equipment over the years. Not having a stop bath removes this cause.

What has been your experience? Will my prints disintegrate without Stop Bath?

No, the stop bath has no influence on the print quality. The quality of your fixer and how well the rinse after the fixer are essential for the quality of your prints.

  • why the anonymous downvotes? Tell me at least when you disagree. I'm open to any discussion, but be warned: my answer comes from decades of experience, I have some arguments.
    – user23573
    Jun 4, 2018 at 14:43

I was recently having trouble with the whites in my fiber prints turning yellow. The first print I made in a session was fine. The next one had a faint yellow stain. successive prints were successively worse. Turned out to be because I was using a water rinse instead of stop bath. As soon as I put acid in the bath the problem went away. Use a stop bath, is my advice.

  • The RC's don't seem to matter as much, but I did notice that my fiber cool tone paper got remarkably warm when not using enough stop bath.
    – SailorCire
    Dec 8, 2015 at 17:59
  • I honestly doubt that it has anything to do with the acid. Did you keep the light out during the "rinse"? What was the water quality of the "rinse"?
    – user23573
    Jun 4, 2018 at 14:47

I use a stop bath simply because of the speed, I can do it quickly and then get the print washing without another waiting step.

Given how very cheap it is, I think it's worth it

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