To stain, or not to stain – Acid and pyro developers

There is a very controversial topic on the Internet. It’s in fact so controversial that I almost don’t dare post about it. It’s that thing about pyro developers and the dye image (‘stain’) they produce. This is seen as a desirable trait, as it apparently helps to mask film grain, and it adds substantial UV density, which is great for processes like carbon printing. Now, the question is – is it OK to use an acid stop and fixer with a staining pyro developer, or will this obliterate this precious dye image? Come in and find out!

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Black is the new black – Pigments for B&W carbon transfer

No, I haven’t given up color carbon just yet, but neither will I leave B&W alone. One issue I’ve been having is that of hue. After all, there’s black, and there’s black: black pigments tend to come in all sorts of hues, so there’s lots to choose from. But a satisfactorily neutral black has evaded me for quite some time – until now!

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(T)issues – A note on pigment dispersion and chroma

I’ve been working with powdered pigments for a (brief) while now and as a result, I’m starting to come to grips with the pros and cons of this approach. Overall, it’s lots of fun – in fact, this is so far my favorite part of the color carbon project. But there are challenges also to this part. For instance, I recently ran into an issue of tissues that didn’t look quite as nice and shiny as they should. And that actually has implications that go far below the surface!

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How to ab-stain? Dichromate stain issues in carbon printing

No, I haven’t given up on the color carbon project. Yet! But there are challenges, and they can be, well, challenging. For one, I’m running into trouble with hue and chroma of the color layers and I’ve been having a hard time figuring out what happens. One probable cause is actually dichromate staining. Let me exstain. Err, explain.

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Fairy dust – Dry pigments for color carbon

Alright, I caved. I had been ogling the website of Kremer Pigmente for a few weeks and ultimately I decided to order some pigments from them. I think it actually makes sense, despite the warnings I was given by multiple people on the forums. After all, dry pigments are challenging to work with. Or so they say…

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Color me purple – Some color developer formulas including C41 and RA4

Despite the modest resurgence of interest in film photography, supply issues remain a concern. This is nothing new; a few years ago, I already worried about this and figured that I wanted to expand my options when it came to in particular color chemistry for C41 negative development and RA4 printing. I started collecting formulas I found online, purchased the necessary chemistry and mixed quite a bit of (mostly) developers myself. Now seems a good time to share my findings with you. If anything, it might be convenient to have some key formulas in one place.

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Roll another one…modifying the Durst RCP20 for RA4 processing

Sometimes I’m just incredibly lucky. Tabletop RA4 roller transport processors are unobtanium these days and if you find one, it is likely to be insanely expensive. I happened across a Durst RCP20 (which in fact is a Thermaphot machine, but Durst sold them under their own brand). These machines have a few drawbacks though, which boil down to them being darn old pieces of equipment. First and foremost, to be able to use mine, I had to convert it to run at the right speed for the current RA4 color paper process. Here’s how I did this.

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Fade to grey – The pigment balance problem

Open any book or web page on color printing and it’ll say at some point that all pigments or dyes used in the process should mix to a neutral grey or black – at least in theory. It’s an issue I’ve been ignoring throughout my color carbon adventures so far. Well, not exactly ignoring, but I didn’t spend sufficient attention to it, certainly not in writing. Allow me to make up for this, at least in part. In this blog, I’ll explore the issue of pigment balance and try and work out a way to determine, at least with rather coarse resolution, a usable pigment balance for color carbon tissues.

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The curve is dead, long live the curve – the linearization game, part 3

After observing a bit of a problem with a lack of linearization and setting myself up for embarking on the effort of linearization, it’s time to describe this actual linearization process itself. It’s going to be a dish with inkjet digital negatives as the main ingredient, broiled in a broth of GIMP with generous lashes of Excel and a good whiff of intuition, topped off with some guesswork for good measure. It’s going to be a bumpy ride!

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Straight ahead– the linearization game, part 2

Previously I wrote about the necessity of linearization: if you print an inkjet digital negative, what densities you can expect from the resulting carbon transfer print are a bit of a gamble. Put differently: the relationship between inkjet negative density and print density is not a linear one. To get color to work reasonably well, I’ll need to linearize my curves reasonably well, too. It’s a bit of a chore, but…well, no but, and not a ‘bit’ either. It’s just a chore. And there’s actually some preparations to be done before I can start with the…err, preparations. (I’m not sure when I’ll get to the actual printing, come to think of it!)

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