Ilford Bromophen 5L: Mixing, Dilution and Shelf Life

Quick answer

Mix the whole 5L pack of Ilford Bromophen powder into 5 liters of water at around 40°C to make a stock solution, then dilute that stock 1+3 with water to create your working tray solution. Store the stock in a tightly capped, full bottle away from light and heat, and mix only as much working solution as you can use in a session. Bromophen is a phenidone/hydroquinone print developer with a long shelf life as stock, but the diluted working solution is the part that ages fastest.

What you need before you open the pack

Bromophen arrives as a powder, so the first job is dissolving it completely rather than guessing at a partial mix. You need a clean 5-liter container, a stirring paddle or spoon reserved for chemistry, a thermometer, and water you are happy to develop prints in. Warm water helps the powder go into solution; very hot water is not necessary and can be uncomfortable to work with.

Work in a ventilated space and add the powder to the water, not the other way around. Powder that clumps on the bottom of the container will stay there unless you stir steadily from the start. If you are mixing the full 5L pack, use the full volume of water stated for the pack so the stock concentration is correct before you dilute it.

• Use a dedicated 5-liter mixing vessel and a separate stirring tool.
• Have a thermometer ready so you can aim for warm, not scalding, water.
• Keep the powder sealed until you are ready to mix the whole batch.

Mixing the 5L stock solution

Fill your container with most of the water first, then add the Bromophen powder while stirring. Continue stirring until no powder remains visible and the solution looks uniform. Top up to the final 5-liter mark after the powder has dissolved, because the powder itself takes up volume and adding all the water first can leave you over the line.

Let the stock sit for a short while before you dilute it for the tray. This gives any stubborn particles time to dissolve and lets you check the solution is clear and consistent. Label the bottle with the mix date so you can track paper developer shelf life rather than relying on memory.

• Add powder to water while stirring, then top up to 5 liters.
• Stir until the solution is uniform with no visible powder.
• Label the bottle with the date you mixed it.

Making the 1+3 working solution

Bromophen is made into a stock solution that is diluted 1+3 for use. That means one part stock to three parts water. If you need 1 liter of working solution, measure 250 ml of stock and add 750 ml of water. Mix only what fits your tray and what you can realistically use in one printing session.

The 1+3 dilution is the standard starting point, not a suggestion to adjust at random. If you change the ratio, you change development time and contrast behavior, so keep the dilution consistent and adjust your print exposure or development time instead. A small measuring jug makes this step repeatable and avoids drifting between sessions.

• Measure 1 part stock to 3 parts water for the working solution.
• Mix only the volume your tray needs for the session.
• Keep the dilution fixed and adjust time or exposure instead.

Storing stock and working solution

Stock solution keeps far better than working solution. Store the stock in a tightly capped bottle, ideally filled close to the top to limit air, and keep it out of light and away from heat. A cool, dark shelf is enough; you do not need refrigeration for a phenidone/hydroquinone print developer like Bromophen.

Working solution is the fragile part. Once diluted, it is exposed to air in the tray and picks up oxidation every time you use it. If you are not printing again within a day or two, it is usually better to discard the tray solution and mix fresh from stock than to store a weak working solution. For print developer storage, the rule is simple: protect the stock, treat the working solution as short-lived.

• Keep stock in a full, tightly capped bottle away from light and heat.
• Do not refrigerate stock solution.
• Discard working solution rather than storing it for long periods.

Capacity and when to replace the tray

Bromophen is described as an economical developer, which is partly about how far the stock goes once diluted. The practical limit is not a fixed number of prints, because paper size, image density, and how long the tray sits out all affect exhaustion. Watch the tray rather than counting sheets.

Signs that the working solution is tiring include longer times to reach the same print density, weaker blacks, and a muddy or flat look in the shadows. When you see those changes, pour the tray out and mix fresh working solution from stock. For fibre based papers, which Bromophen is especially recommended for, development is slower than RC and the tray works harder, so check results more often.

• Judge capacity by print results, not by a fixed sheet count.
• Replace the working solution when blacks weaken or times stretch.
• Check more frequently when printing on fibre based paper.

Step-by-step Bromophen workflow

1. 1. Mix the full 5L stock: Add the Bromophen powder to warm water while stirring, then top up to 5 liters. Common mistake: adding all the water first and stopping short of the final volume, which makes the stock too strong. Checkpoint: the solution should be uniform with no powder on the bottom before you dilute.
2. 2. Label and store the stock: Pour the stock into a tightly capped bottle filled close to the top and keep it out of light and heat. Common mistake: leaving the stock in an open mixing jug where it oxidizes. Checkpoint: write the mix date on the bottle so you can track shelf life.
3. 3. Dilute 1+3 for the tray: Measure one part stock to three parts water, for example 250 ml stock plus 750 ml water for 1 liter. Common mistake: eyeballing the ratio, which changes development time and contrast. Checkpoint: mix only the volume your tray needs for this session.
4. 4. Develop and watch the tray: Develop your prints at your normal time and dilution, and watch for weaker blacks or longer times. Common mistake: continuing to use a tiring tray because the sheet count is not high. Checkpoint: replace the working solution when results change, not on a fixed schedule.
5. 5. Discard working solution, keep the stock: Pour out the diluted working solution after use if you are not printing again soon, and mix fresh from stock next time. Common mistake: storing diluted working solution for weeks and expecting it to behave like fresh. Checkpoint: the stock is the long-life component; the working solution is the short-life one.

Product facts

• Ilford Bromophen Paper Developer - 5L: Ilford Bromophen is an economical phenidone/hydroquinone powder print developer with a long shelf life, supplied as a 5L pack for dish or tray developing. The long stock shelf life is why you can mix the full 5L batch without rushing to use it all at once.
• Ilford Bromophen Paper Developer - 5L: Bromophen works with all black and white RC and FB darkroom papers but is especially recommended for fibre based papers. If you mainly print on fibre paper, this developer is aimed at your workflow; RC users can still use it but may see less of its intended benefit.
• Ilford Bromophen Paper Developer - 5L: Bromophen is made into a stock solution that is diluted 1+3 for use and delivers a slightly warm image tone with most papers. The 1+3 ratio is the working dilution to measure from, and the warm tone is a look to expect rather than a neutral black.