What’s in the Unicolor C-41 Kit and What Size Should You Buy?

Someone just asked me what’s in the Unicolor C-41 kit that we sell here, and it reminded me that I went to a film photography meetup recently where a couple of people asked me about that, so I thought I’d write a quick post about it:

When you buy the kit, what you receive is a cardboard box with a few things inside:

  • A short, but very clear and useful instruction booklet
  • The C-41 Developer powder, packaged in a vacuum-sealed foil bag
  • The Blix Part A powder, packaged in a vacuum-sealed foil bag
  • The Blix Part B powder, packaged in a vacuum-sealed foil bag
  • The Stabilizer powder, packaged in a little zip-loc bag

I’m going to go through each of these briefly:

  1. The Developer powder is what you’re going to use for your first step of developing C-41 film. This (like all the C-41 chemicals) comes in powder form, so that it has a long shelf life, and once you’re ready to start developing film, you mix it with water and put it in a bottle and make sure it’s all dissolved (the booklet should explain this – basically you mix the powder in while stirring at a high temperature, and then possibly leave it a while to dissolved fully).
  2.  The Blix Part A and Part B powders are packaged separately, because they contain chemicals that react when they’re mixed up. When you’re ready to develop these, you’ll mix both of them together with water, and you’ll actually see a chemical reaction when they come in contact. This is actually pretty cool to see, you just have to make sure you don’t mix them too fast, and you use a big enough container, because they create an endothermic reaction, and there’s a bit of bubbling and vapor. Once you mix these, you’ll have a liquid solution that you use for the second step of developing.
  3. The Stabilizer powder is just a very small amount of white powder in a zip-loc bag (the other bags are strong, vacuum-sealed, opaque bags). After you mix this with water, you use it in the third stage of developing. Your film is completely developed and ready to scan/print/etc. at this point, but the stabilizer treats and hardens the actual film to avoid any degradation over time.

And there you have it, those are the 4 things included in the kit. I should also mention that the instructions in the kit are very well written. It’s just a little paper booklet that’s short, but is so nice and readable, and contains all the information you need, explained very, very clearly. I was actually really surprised at how user-friendly the booklet is when I first saw it.

So what size kit should you buy?

The main things you want to think about when you decide on a size are these:

Shelf Life: As long as you keep air out of your storage bottles (usually done by squeezing extra air out just as you seal them), your chemicals can last for quite a long time (at least several months, if not longer), and most people who do this are able to get a lot of rolls out of each kit. The instructions say you can get up to 12 rolls done before there’s any degradation, but after that point, any loss in color or contrast is still pretty gradual, so it’s very common to get a lot more out (I’ve heard people report from 20-35+ from a 1 Liter kit). So what this means is that if you think you’re only going to home develop 6 rolls in a year, it’s probably not worth buying the 2L kit, because your chemicals may wear out before you have a chance to fully use the kit.

Price: Buying the 2L kits gets you a pretty good discount – you only pay about 50% more than buying a 1L kit. Apart from lowering your cost per roll, this also gives you a little leeway – for instance, if you buy a 2L kit, develop a bunch of film with it, but then your life gets busy and don’t get back to it for a while, and the chemicals get old, your cost per roll might still wind up the same as if you had bought the 1L kit.

Bottle Size / Storage: Unlike B&W chems, with C-41, you are supposed to mix all the chemicals at once, then store them in bottle until you’ve exhausted them. This means that if you buy the 1 Liter kit, you need 3 bottles that each hold 1L of liquid. If you buy the 2 Liter kit, you need 3 bottles that hold 2L. We sell the Delta Datatainer chemical storage bottles in each of these sizes, which are great, high quality bottles, meant for this task. However, if you want a less permanent option, you can use plastic pop bottles (just make sure to rinse them very well, and don’t expect them to last forever).

So whichever size you use, you need to think about storage. You’re going to have 3 bottles to put away, and 2L bottles take up more room than 1L.

Hope this article helps, and I’ll repeat the link to buy the Unicolor kit (as well as changing bags, developing tanks, etc) here.

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