Ilford Ilfostop Stop Bath 500mlis a low odor acid stop bath. Normally, when development is completed, films and papers are subjected to a stop bath rinse. This immediately halts the developing process by neutralizing the developer.

Following this, the film or print is exposed to fixer (hypo). The advantage of the stop bath process is that it extends the life of the fixer. Some people do not use stop bath and, in that case, you must use an inordinate amount of fixer to erase the effects of the developer. If a stop bath is not available or chosen, the film or print should be thoroughly soaked in a water bath or rinse - with frequent changing of the water supply. Stop bath gives you the assurance that your developing stage is completely "over" and that none of the developer will be carried over to the fixer.

Ilfostop contains an indicator dye that is pH sensitive and changes color from yellow to purple as the stop bath becomes exhausted. It is specifically recommended for dish and tray processing of paper or deep tank processing of film.

It should be noted that Ilford recommends that gloves, eye protection, apron or overall be worn when handling and mixing all chemicals.

Liquid Concentrate    Use For Black and White Film    Minimal Odor    Use for Tank, Tray or Dish Processing    Extends Life of Your Fixer    Goes Yellow to Purple When Exhausted    Normal Dilution is 1+19

Ilfostop concentrate will keep for 5 years in full airtight bottles and 12 months in half full tightly capped bottles

It will stay fresh as a working solution for 7 days

500ml will make 10 liters of working solution

A full working strength solution will produce 150 135-36 or 120 films or 600 20.3x25.4cm (8x10") RC prints or 300 20.3x25.4cm (8x10") FB prints

Related Questions and Answers

Q: 1. 1. Can stop bath be reused?2. For a 500ml bottle of concentrate, whats the best way to use and preserve? mix per use? how much fits in a tank? do i get a new empty bottle and mix diluted in there and pour back in there after use?

A: Yes, IlfoStop can be reused until the indicator dye goes from yellow to purple. The concentrate will keep for 5 years in a full airtight bottle and 12 months in a half full tightly capped bottle. In working strength, it provides 7 working days. The amount that goes in the tank depends on how many rolls are being developed or the size of the print. A new empty bottle should be used to store the chemical after being mixed and once it has been used for development for reuse at a later date.

Q: 2. Will this work with graded paper (not multi grade or poly contrast papers)?

A: Yes this fixer can work with graded papers.

Q: 3. will this work with kodak polycontrast iii?

A: Yes, it similar to Dektol.

Q: 4. What's the dilution ratio?

A: 1+19 Dilution

Q: 5. If I use it on b&w films development,does it also request 20 degree temperature?

A: It is not as critical as developer temperature. Here is what the instructions say:ILFORD ILFOSTOP 10 seconds About 20C/68Fstop bath diluted 1+19 preferably nowarmer than25C/79F and nocooler than15C/59F

Q: 6. How long will the chemical last if I start using it?

A: Once mixed, the Multigrade Developer will last 6 months in a sealed container.

Q: 7. Can I develop films with this?

A: Technically, yes. But for best results, you are significantly better off using actual film developer. Times and results will vary greatly because the concentration/strength/developing time and grain structure will be quite different. You will also have to experiment with dilution for best results.

Q: 8. After mixing 1:19, how long to leave the film exposed to the stop solution before fixing?

A: 30 seconds with continue agitation. I am chemist. You are neutralizing using a week acid, if your time goes some seconds over it does not have huge impact.

Q: 9. Can this be used to stop a D-76 developer?

A: Hi yes, , this stop bath works with kodak d-76

Q: 10. After mixing the concentrate with water. What is the maximum time to be able to reuse it again?

A: The working strength is good for 7 days.