Darkroom & Dev Kit

Large scale printing with a Jobodrum – By Thorsten Wulff

June 9, 2020

Since last year I had this box with 50 sheets of Ilfospeed Multigrade paper in 40x50cm, (16×20 inch), but only one fitting developer tray. So with a lot of time on my hands in the last weeks I thought why not make some larger prints of the images I took last summer on Omaha beach. Not inclined to spend 100 Euros or so for the two needed further trays my idea was to get a pair of those clear plastik containers from Ikea, but they were closed like everybody else.

So while I tried to come up with a contraption large enough I remembered the very well stocked darkroom of my friend Cäsar. Working as an art teacher he had enough time and the means to tinker with lots of photographic equipment, like one of those Jobo CPE developer entrapments for film and paper. If you don‘t know those machines, they allow you to keep your chemicals and tank at a certain temperature via a water bath, agitate the tank, and you switch chemicals via rising a lever. Jobo still makes them, like this current CPE3

The method is very handy for color pictures for example. So it reminded me of the JOBO drums for developing paper without the need for huge trays, and lots of chemicals to fill them. But you don‘t need the machine for developing larger sized paper, one of the Jobo drum tubes is enough. I went to ebay and found one fitting for 40×50 paper for 30 Euros, including shipping. It arrived, unused and still in the original box, made more than 30 years ago in West-Germany.

The drum is one long cylinder topped with a revovable lid, from the same robust material like the Jobo or Patterson film tanks. The lid contains a funnel for inserting the chemicals, with a holding pod for 200ml of fluid.

All you need to do is prepare the developer, stop bath and fixer in their respective bottles. The construction of the pod allows you to fill in the developer while the drum stands upright, it will be released via slits into the cylinder as soon as you lever the drum horizontally.

In the darkroom you expose the image in the enlarger (I tested time and contrast beforehand with strips developed in handy 18×24 trays), roll the sheet together and place it in the tube. The 40×50 paper fits snugly into the drum, with only a narrow strip remaining between top and bottom. You replace the lid, fill about 200ml of developer into the funnel and switch on the white light, or leave the darkroom, if you like.

All you need now is an area to roll the tube. A distance of one meter is enough, I used the sticker as a marker for start and stop and rolled the tube up and down on the floor. The top of a washing machine is a good spot, but mine is occupied by the enlarger. You seal the drum with a red Jobo lid, and because of the small amount of liquid there is no danger of developer spilling out on your carpet.

After 1.5 to two minutes rolling the developer is done, you simply drop it back into the bottle for further usage. Repeat the process with Stop (or water) and Fixer, and your done. Open the lid, and a nice developed print awaits you.

Just clean and dry the tube, and you are ready to go for the next print. There was no problem of fixer residue between pictures.

The Jobo drum is a good alternative to a set of huge trays, and the tiny amount of chemicals you need is amazing. I would guess that you need to put 1.5 litres of developer in a 50×60 tray to float the prints, here you are done with a lot less. The drum gives you the ability to develop large prints even if you have a temporary darkroom in your flat, it is a quick, easy and clean process.

As usual, best from Berlin, and stay safe everybody!

Thank you for your time. If you interested in more of my work, you can find it at
You can find more darkroom and dev kit reviews here

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  • Reply
    Terry B
    June 9, 2020 at 7:15 pm

    Thorsten, It is a pity that the size of the prints precludes our seeing your results. Not something that I ever used, but I do recall the Jobo Thermodrum system as being quite compact and very useful.
    One small point, the word you are looking for is contraption, not entrapment. They have completely different meanings. :p)

    • Reply
      June 9, 2020 at 7:52 pm

      You got me there, Terry, thanks… you know germans, we have vays of making you talk!
      I hope to get a space for hanging the images, after this years D-Day celebration was basically called off.
      The prints turned out quite nicely on the Multigrade after I allowed myself some time for testing on small strips,
      the best size I can offer you right now is here:

      • Reply
        Terry B
        June 10, 2020 at 11:55 am

        Thorsten, lovely sense of humour. Mum’s the word, as we English might respond!

        • Reply
          June 10, 2020 at 12:12 pm

          Dear Terry, as a westgerman luckily I grew up on british humour!

          • Terry B
            June 10, 2020 at 12:44 pm

            Thorsten, great to hear. But I see you haven’t lost the German proclivity to join up small words into a larger one. I’m guessing that a “westgerman” is not a variety of the geranium flower, but a person brought up in what was West Germany, i.e. a West German.
            Full marks for the spelling of “humour”.😁

          • thorsten
            June 10, 2020 at 2:48 pm

            Oh Terry, you have no idea how tough it is to keep all those words from running into each other! I assume you are familiar with Mark Twains essay «The Awful German Language» from A Tramp Abroad, in which he dissects the german compulsive disorder of creating compound words. I for myself are from the baltic coast, the old hanseatic town of Lübeck. Northerners are supposed to be quiet, serious folk, at least if you ask Rhinelanders or even Bavarians ;))

          • Terry B
            June 10, 2020 at 9:59 pm

            Hi, Thorsten. No, I ‘m not familiar with Mark Twain’s essay, but a quick check on Amazon shows they have a Kindle edition, so I bit the bullet and bought it. I rather suspect that I will enjoy the humour.
            I was aware that you lived in Lübeck from a previous exchange we had when I referred to a Bach recording I was listening to by Ernst-Erich Stender playing on the organ at St. Marien. This was prompted by one of your images of the interior of a cathedral or church, and which if memory serves was St. Marien.
            I’ve viewed your images. The shot of the elderly lady is wonderful and I’m betting on she has a story or two to tell.

          • thorsten
            June 11, 2020 at 8:24 am

            Right! Yes, St. Marien it is, you would love the spiral stairs up there to the organ, tightly wound and each one of a different height, worn out by centuries of people climbing them. This lady is in her nineties and lived all her life in a little house looking out over the beach. She mistook me for one of of her sons friends.

      • Reply
        Terry B
        June 12, 2020 at 2:33 pm

        Thorsten, what an hilarious read. I particularly liked the reference to the split verb and finding the second part on the next page of German newspapers. All good stuff.

  • Reply
    June 9, 2020 at 7:31 pm

    What is this magical place where you can buy JOBO drums for cheap!? I was looking for them recently for color printing and they all seem to cost €50-80 here, ex €30 shipping. Oh well, I’ll have to keep my eye on it. Until that time I’ll have to make do in the pitch dark… 🙂

    Great results though!

    • Reply
      June 9, 2020 at 7:42 pm

      No problem Richard, you can borrow mine anytime ;))

  • Reply
    June 9, 2020 at 9:36 pm

    really useful article, thanks thorsten, i was looking at one of these to do colour prints but was unsure. my darkroom is not light tight (very close). If you were doing colour would you do test strips in trays initially do u think?

    • Reply
      June 10, 2020 at 7:42 am

      Oh absolutely, Phlogger, I would do that. But I have to admit that even in my heyday thirty years ago I stuck to B&W… and I still wonder how I managed to get these prints spot on in 1987, usually without test strips.

  • Reply
    Sergio Palazzi
    June 9, 2020 at 10:10 pm

    The very few times I printed 50×70 on RC Ilford paper I used my trays for 30×40, along the diagonal, lifting up and down the sheet in the bath taking care not to leave my fingerprints. I think that the last pack I bought in XX century should be somewhere with some remaining unexposed sheets 😉

    • Reply
      June 10, 2020 at 7:37 am

      I put a wooden plank on my bathtub to rest the trays on it, so space was an issue there. But of course that is a very practical way to handle the size…

  • Reply
    Sergio Palazzi
    June 9, 2020 at 10:16 pm

    I remember that I managed to find a PVC or PP tube of 20 cm ø to use it the same way, but it ws too difficlt to close at the extremities. Probably I used it in the garden.

    • Reply
      June 10, 2020 at 7:38 am

      That was actually my first idea… but then I thought about all the developer that would leave on the floor ;))

  • Reply
    Lasse Løvstrøm Madsen
    June 14, 2020 at 12:23 pm

    Great manual, i am looking into starting developing on paper, and the drums just seems so much more handy than anything else.
    Do you put the exposed side of the paper towards the center of the drum or the side.
    Have you tried multiple papers in one drum (if they perhaps were a smaller size) ?

    • Reply
      June 15, 2020 at 8:24 am

      It’s the exposed side to the center. You can stuck smaller sizes into them which I have not done yet, Lasse, but it’s very practical for lets say you want 6 prints 18×24 from the same image. For test strip purposes you still need a tray, but after you decided on exposure time and gradation for a certain image, this is a good way to go. I had to learn this the hard way last year, when I hurried through my D-Day images by the roll, and not painstakingly by the single image, on baryt paper…

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