color – Koraks tinkers

Creative RA4 – Bleach and redevelop

Straight printing on RA4 paper is great fun and it’s what I do most of the time when I print color in the darkroom. But the RA4 process has several tricks up its sleeve. The other day I decided to revisit one of those tricks I had played with briefly some years ago: bleach and redevelop. Here’s an example of what it does and how it’s a useful took in boosting print contrast without saturation going overboard.

Pixels, not grains – Why RA4 paper is ‘digital’, and why this matters (not?)

Look at the back print of some papers, such as FUJIFILM’s Crystal Archive Supreme HD, and the word ‘digital’ features prominently. Indeed, I’ve been told that current Fuji RA4 color papers are exclusively intended for digital exposure. But does that mean we can’t use them anymore for optical enlargements?

Between the lines – The importance of interlayers in RA4 color paper

‘Today I learned’…a lot, in fact! More than enough to fill a couple of blogs, but let’s start with this one. Did you know that color paper has layers that you can’t see, that are actually designed to be invisible, but that play a huge role in the visual aspects of the paper and the images on it? Well, now you do! They’re the interlayers, and they are quite essential, as it turns out. I’ll try to explain.

Color carbon made feasible, part 1: halftone screens

In my previous blog post, I outlined a couple of tough challenges I met in the color carbon project. These challenges are partly inherent to the carbon transfer process, and partly stem from working with digital negatives, in particular continuous tone negatives. In this blog, I will outline the two main components to a solution to these challenges: halftone screen negatives and sensitizer-incorporated tissue.

Color carbon and digital inkjet negatives: challenges

It’s been awfully quiet on the color carbon front, hasn’t it? Well, that’s partly accurate. I haven’t done as many test strips these past two weeks as I’d been doing before, and the reason is that I’m at a crossroads with this project now. Having learned lots, it’s also becoming clearer now what I’m dealing with. The question is – how to proceed? Let’s start with exploring some of the challenges I’m currently facing, which all happen to revolve around consistency and linearity.

Easy way out – Inkjet on ‘DIY’ papers

No, I haven’t given up on color carbon yet. But as I was messing with the inkjet printer anyway, making hundreds of digital negatives and greyscale tests, at some point I got experimental in that direction as well. You see, the thing with inkjet is that I just don’t like most inkjet papers. They’re very high-tech and offer great gamut and dmax. But they don’t have much subtlety to them and the paper surface is always lifeless to me. The exception is the (rather pricey) inkjet baryta papers that indeed resemble fiber-based B&W papers. But couldn’t we expand our choices a bit, perhaps by trying something ourselves? Well, turns out, we can…read on!

(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!

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.

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.

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.