How to Use Tetenal Eukobrom AC Paper Developer
By WALKENS House of Film | Published: 2026-10-28
Category: How-to Guides
Learn how to mix, use, and store Tetenal Eukobrom AC for crisp black-and-white prints, with dilution ratios, tray handling, and common mistakes to avoid.
Quick answer
Mix Tetenal Eukobrom AC at 1+4 to 1+9 with water, develop your black and white paper in a tray or tank, and stop, fix, and wash as usual for clean, neutral-black prints.
Why dilution matters
Eukobrom AC gives you flexibility: a 1+4 dilution works faster and yields deeper blacks, while 1+9 extends the working life and is more economical. The 1L bottle develops up to 40 m² at 1+9, so it's a solid choice for regular printing sessions without constant remixing.
The formula is free of hydroquinone, which is a common irritant in many paper developers. That doesn't mean you can skip gloves, but it's a more pleasant option for darkroom work.
Tray vs. tank development
Eukobrom AC is designed for trays, drums, and small desktop tanks. In a tray, you can watch the image appear and pull the print when the contrast looks right. In a tank or drum, you get more consistent agitation and less oxidation, which is handy when you're making multiple identical prints.
If you're new to paper development, trays are easier to learn because you can see the print develop in real time. Tanks require you to trust your time and temperature, but they're cleaner and use less chemistry.
Step-by-step development
- Mix the working solution: Dilute Eukobrom AC with water at 1+4 for normal contrast or 1+9 for a longer-lasting, more economical solution. Use a measuring graduate and stir well. Aim for 20°C (68°F) for consistent results. Check the temperature before starting; if it's off, adjust with a water bath rather than guessing.
- Develop the print: Slide the exposed paper into the tray or tank, face up in a tray, and agitate gently. Typical development time is 1-3 minutes at 1+4, but always follow the paper's recommendations and your test strip. Watch for the image to reach full contrast without fogging. If the print looks too dark or too light, adjust the exposure, not the development time, to keep contrast consistent.
- Stop, fix, and wash: Move the print to a stop bath for 30 seconds, then fix according to your fixer's instructions. Wash thoroughly with running water or a wash aid to remove all chemistry. Hang to dry. Use fresh fixer; exhausted fixer can cause prints to fade over time.
Product facts
- TETENAL Eukobrom AC B&W Paper Developer 1L: Eukobrom AC is a new formula without hydroquinone, for all b/w photo papers, and produces deep blacks with low stain and neutral black tone. You get clean, crisp prints with less chemical odor and reduced risk of staining, making it easier to achieve consistent results.
TETENAL Eukobrom AC B&W Paper Developer 1L
