• CineStill CS41 Powder Kit (Color Developer packet; Blix Part A and Part B packets)
• Film developing tank and reels (e.g. Paterson or similar)
• Measuring jugs and mixing bottles (preferably amber to protect chemistry from light)
• Accurate thermometer (for 39 °C / 102 °F control)
• Timer or stopwatch
• Protective gloves, safety goggles and protective clothing
• Scissors
• Light-tight changing bag (or access to a darkroom) for loading the film
• Drying clips

Optional but highly recommended: The AGO Film Processor monitors your chemistry temperature and adjusts development timing automatically, so you always get accurate results without babysitting a water bath.

• Place 600-700 ml of water at 38 °C (100 °F) into a clean container
• While stirring, add the entire contents of the Color Developer packet
• Stir well until fully dissolved
• Top up with water at 38 °C to reach 1000 ml total

Shelf life once mixed: 2-6 weeks in a tightly sealed, completely filled storage bottle.

• Place 600-700 ml of water at 38 °C (100 °F) into a clean container
• While stirring, add Part A and stir well until dissolved
• Pour the solution into a 1000 ml storage bottle
• Add Part B. Combining Parts A and B creates an endothermic (cooling) reaction. Allow approximately 5 minutes for the reaction to complete and the solution to settle
• Pour the solution back and forth between the pitcher and bottle a few times to mix thoroughly
• Top up with water to reach 1000 ml total

Shelf life once mixed: 8-12 weeks in a tightly sealed, completely filled storage bottle.

No stabilizer is included in the powder kit. Modern colour films contain stabilizers in the emulsion that are released naturally through the two-bath process, so a separate stabilizer is not required. If you prefer to use one, a final rinse of distilled water with Hexamine (fungicide) and/or Photo-flo (surfactant) works well. Film more than 20 years old may require a formalin or formaldehyde-based stabilizer preservative.

Step 1 Pre-Soak: developer temperature, 1:00 min Optional

A brief pre-soak with water at developer temperature helps bring the film and tank up to the correct temperature before chemistry is added, reducing the risk of a cold-start temperature drop affecting your results. No agitation needed during this step.

Using the AGO Film Processor? If you are skipping the pre-soak, start your developer 2-4 °C higher than the target temperature to compensate for the cold tank absorbing heat when the chemistry first enters. The AGO will track the actual temperature and adjust timing accordingly.

Step 2 Developer: 39 °C (102 °F), 3:30 min

This is the most critical step. The developer reacts with the exposed silver in your film to create the visible image. Temperature accuracy here matters a great deal as even small shifts will affect your colours and density. The AGO Film Processor monitors this for you and adjusts timing accordingly.

Agitation (manual): continuous for the first 10 sec, then 4 inversions every 30 sec.

Step 3 Blix: 24-40 °C (75-105 °F), 8:00 min

The Blix combines the bleach and fix stages into one bath. It converts the metallic silver created during development and removes it, leaving only the stable colour dye image. Your film is no longer light-sensitive after this step and the lid can come off the tank. Same agitation as the developer step.

Agitation (manual): continuous for the first 10 sec, then 4 inversions every 30 sec.

Step 4 Wash: 24-40 °C (75-105 °F), 3:00 min

Rinse with running water, or fill the tank with water, agitate, and empty it. Repeat until the wash time is complete. The datasheet recommends filling and emptying the tank 7 times. This clears Blix residue from the film before the final rinse.

Step 5 Stabilizer / Final Rinse: room temperature, 0:30-1:00 min Optional

A final rinse of distilled water with Hexamine or Photo-flo helps protect the dye layers and reduces drying marks. Agitate gently for the first 15 sec; no further agitation is needed. Modern colour films contain stabilizers in the emulsion released through the two-bath process, so this step is optional.

⚠ Do not rinse the film after the final rinse step

• Temperature matters most during development. Keep your developer at 39 °C (102 °F) as even small shifts affect colour and density. Insufficient agitation will shift colours toward red; excessive agitation shifts toward cyan.
• The AGO Film Processor monitors chemistry temperature throughout the process and adjusts timing automatically, removing the guesswork entirely.
• Keep everything very clean. A few drops of Blix contaminating the developer can destroy it entirely. Use separate, clearly labelled containers and stir sticks for each chemical.
• Use water at your target processing temperature when mixing. This reduces warm-up time before your first session.
• When mixing the Blix, allow the full 5 minutes for the endothermic reaction between Parts A and B to complete before topping up to final volume. The solution will feel noticeably cooler during this reaction.
• Reusing the developer: the developer can be reused across multiple sessions. When reusing, combine used and unused developer to make a full 1000 ml working volume and increase development time by 2% for each roll previously processed. For example, if you developed 4 rolls in your previous session, increase development time by 8%: 3.5 min x 1.08 = 3.78 min. Note: reusing developer is not recommended for push processing.
• Reusing the Blix: unlike the developer, the Blix does not require any time adjustment when reused.
• Store all chemistry in sealed bottles filled completely to the top to minimise air contact. Label everything clearly before storing.