RA-4 Reversal with Jagglé: Turning Colour Paper into Positives

Introduction

RA-4 reversal is one of those processes that feels like pure alchemy. Instead of making colour prints from negatives, you can expose RA-4 colour paper directly and process it so the result is a positive colour print.

The look is unique: luminous, vivid, and sometimes a little unpredictable. It’s a playground for analogue photographers who enjoy experimentation. With Jagglé’s RA-4 kit — which combines RA-4 paper, Neutol Eco developer, colour chemistry, and the Jagglé Daylight Cassette — you can explore this colourful process without needing a full darkroom.

The RA-4 Reversal Process

Here’s the process in a nutshell:

  1. First Developer (B&W)
    After exposure, the print is developed in a black-and-white developer in darkness. This converts the exposed silver halides into metallic silver.
  2. Wash + White-Light Exposure
    The print is washed, then briefly exposed to white light. This fogs the remaining silver halides that were not developed in the first step.
  3. Colour Developer (RA-4)
    Now the colour developer gets to work. Since the silver from the first step is already “used up,” the colour developer only acts on the areas fogged by the white light. As silver forms, dyes are created, giving rise to the positive colour image.
  4. Bleach-Fix (Blix)
    The Blix converts metallic silver back into silver halides, then dissolves them away. What’s left is purely the colour dyes.
  5. Final Wash / Stabiliser
    A good wash (and stabiliser if required) finishes the process, leaving a stable, dye-based colour print.

At the end you’re holding a positive colour print, not a negative. It’s tangible magic.

ISO and Exposure Guidelines

RA-4 paper is not nearly as fast as film. Expect much lower ISO values:

  • Indoors with heavy filtration → ISO 1–2
  • Outdoors in sunlight with filter pack → ISO 5–8
  • With pre-rinsed paper and good filtration → up to ISO 10–12

These values are only starting points. Your exact speed will depend on light source, filters, and how you prepare the paper. Bracket your exposures generously when beginning.

Pre-Rinsing and Pre-Flashing

Two tricks that can make your life easier:

  • Pre-rinsing: A quick water rinse before exposure helps remove the paper’s blue base mask. This can improve colour balance and make the paper act slightly faster.
  • Pre-flashing: Giving the paper a very faint, uniform light exposure before the main image exposure can help bring up shadow detail, tame contrast, and even tweak colour balance. It’s a subtle but powerful tool.

Filtration: Correcting for Colour Balance

RA-4 paper is designed for printing from colour negatives, which carry an orange mask. When you use it for reversal, that mask isn’t there, so you must filter the exposing light to compensate.

Filtration serves two purposes:

  1. Correcting for the missing orange mask
  2. Balancing for the colour temperature of your light source (daylight, tungsten, LED, etc.)

You can start with multigrade filters — many photographers have them already, and they can help balance out excess blue or green. Yellow and magenta filters are most commonly needed, though a warming filter (such as 85B) can be useful in sunlight.

Think of filtration not as a burden but as part of the creative process: you can shift the look of your prints simply by swapping filters.

Working with Jagglé Cassettes

The Jagglé Daylight Developing Cassette makes RA-4 reversal more approachable, especially for large format work:

  • Load in a darkbag: slip your RA-4 sheet into the cassette without needing a darkroom.
  • Expose in camera or enlarger: the cassette protects your paper until you’re ready.
  • Process in daylight: after exposure, the cassette sits on the developing tray, forming a light-tight tank. All the chemistry steps can be carried out without returning to a dark room.
  • Easy light exposure: for the crucial re-exposure step, simply lift the cassette, fog under white light, and continue.
  • On-location freedom: perfect for taking colour reversal out of the darkroom and into the field, workshops, or wherever creativity strikes.

With Jagglé, RA-4 reversal stops being confined to a lab and becomes something you can explore in real time.

Conclusion

RA-4 reversal is a joyful process — colourful, surprising, and immensely rewarding. Each print is a one-of-a-kind positive image straight out of the chemistry tray.

By combining the Jagglé cassette with RA-4 paper, Neutol Eco, and colour developer, we’ve put this process into a portable, accessible kit. Whether you’re chasing luminous colour in the studio or experimenting in the field, RA-4 reversal is your invitation to play with light, chemistry, and analogue colour in a fresh way.

Back to blog