I’m currently using the CineStill kit below to develop color medium format film. This kit is easy to use and fairly inexpensive, around $30 and will develop 4 or 5 roles of 120 film. Your results may vary.

Temperature is more important when developing color film. The instructions are easy to follow but you will need a temperature controlled water bath of some sort. I use a sous vide warmer in a tub of water. These chemicals shouldn’t go down the drain so that adds an additional complication with storage and proper disposal of waste. I mix and process right away. That gives me three bottles of solution, a developer, a blix, and a final rinse.

I use a Patterson tank for medium format film. This allows me to develop outside of the darkroom. I also add a bit of wetting agent as a final step. One drop of wetting agent to 500ml of water is plenty. Too much wetting fluid will leave a residue on the film. An alternative to Photo-Flo is just to use distilled water as a final rinse.

The Patterson tank is great for developing a roll of film. This particular tank can develop both 35mm and 120 film. The only issue with the tank is that you should make sure the top funnel is locked into place when dumping. It doesn’t really lock, but it needs to be engaged with the retaining tabs while dumping liquid or the entire funnel with fall into the sink, possibly exposing your film. I turn the funnel as far as it will go and keep pressure on it while dumping liquid.

The film holder of the Patterson tank is typically sold separately. I bought one that does both 35mm and 120 film. I can’t remember the last time I developed a role of 35mm but I suppose if a friend needs some developing it’s nice to have the option in one spindle.

Once the film is developed I hang it to dry for a few hours. There’s very little humidity in my house. Drying times will very. Once dry, I scan with the Epson V850 Pro. I fluid mount the best negatives using the fluid mount holder and Kami 2001 scanning fluid. This might be the only scanning fluid available online. It’s made by Aztek, Inc. It dries very quickly, making cleanup surprising easy.

Here’s a more detailed explanation:

How to Develop Color Medium Format Film at Home (C-41 Process)

Developing color medium format film at home can seem intimidating, but with the right tools and careful temperature control, it’s an accessible and rewarding process. Whether you’re shooting 120 film with a Hasselblad, Mamiya, Pentax 6×7, or a modern medium format camera like the Fujifilm GF670, this guide will walk you through how to develop your C-41 film at home with consistent and professional results.

What Is C-41 Film?

C-41 is the standard chemical process used for developing color negative film. Most consumer and professional color films (like Kodak Portra, Gold, Ultramax, and Fuji Pro 400H) use this process. Unlike black and white film, C-41 requires precise temperature control—typically 102°F (39°C)—to ensure correct color balance and image quality.

What You’ll Need

1. Film and Tank Supplies

Exposed 120 medium format roll(s)
Film developing tank (e.g., Paterson or JOBO-style tank with 120 reel)
Changing bag (optional but helpful for loading film in daylight)
Scissors and bottle opener (if developing 35mm too)

2. Chemicals

C-41 chemical kit (e.g., Cinestill Cs41, Tetenal, Unicolor, or Bellini kits)
- Typically includes:
  - Developer
  - Blix (bleach + fixer)
  - Stabilizer

3. Equipment for Temperature Control

Sous-vide heater or temperature-controlled water bath
Thermometer (accurate to ±0.1°F/°C)
Measuring cylinders and storage bottles (preferably amber plastic or glass)
Timer or stopwatch

Step-by-Step C-41 Development Process

Step 1: Prepare Chemicals

Mix the developer, blix, and stabilizer according to the kit’s instructions. Label and store them in separate bottles. Heat each chemical to 102°F (39°C) before use.

Step 2: Load the Film

In total darkness (or using a changing bag), load the 120 roll onto a reel and place it inside the tank. Seal it tightly.

Step 3: Develop

Pour in the developer (102°F)
Agitate continuously for the first 10 seconds, then 4 inversions every 30 seconds.
Time: Usually 3 minutes 30 seconds to 4 minutes, depending on the kit.
Pour out the developer (can be reused).

Step 4: Blix (Bleach + Fix)

Pour in the blix at 102°F
Agitate the same way: first 10 seconds, then 4 inversions every 30 seconds.
Time: Usually 6–8 minutes
Pour out the blix (also reusable).

Step 5: Wash

Rinse the film thoroughly with water at 95–105°F (35–40°C) for 3–5 minutes.
Optional: Use distilled water for the final rinse to avoid mineral spots.

Step 6: Stabilize

Pour in the stabilizer (room temperature).
Gently agitate for 1 minute.
Do not rinse after stabilization.

Step 7: Dry

Carefully remove the film from the reel.
Hang in a dust-free area using film clips or clothespins.
Let dry completely (about 2–3 hours).

Tips for Success

Consistency is key. Use a sous-vide or aquarium heater for stable temperatures.
Avoid cross-contamination between developer and blix.
Use gloves when handling chemicals.
Reuse chemicals according to the kit’s instructions, but mark how many rolls have gone through.

Optional Tools That Help

JOBO processor for fully automated rotary processing
CineStill’s temperature control system with water bath
Reusable chemical syringes for accurate dosing

Final Thoughts

Once your negatives are dry, you can scan them at home using a flatbed scanner like the Epson V600/V850 or a dedicated film scanning setup. Many photographers developing at home find that their results match or even surpass commercial labs—plus, you get complete creative control.

With some basic investment and care, you can unlock the full potential of medium format color film in your own darkroom.

I’ve found that adding marbles to your stored solution is a great way of keeping the fluid topped-off so that air does not oxidize your developing solutions. This will greatly extend the life of your developing solutions.

How I develop color film