Rolling – Gearing up DAS carbon printing

Yeah, I’ve been silent on my blog. In case you’re wondering: no, I haven’t given up on anything, given my recent struggles with DAS carbon. In fact, quite the opposite! Since figuring out (at least as far as I can tell, for now) the process limits, I’ve been shifting into gear with monochrome DAS carbon and it’s been going remarkably smoothly. “I Ate’nt Dead“, as Granny Weatherwax used to write!

Frustratingly, I just don’t get around to maintaining this blog as much as I’d like to. For instance, this particular entry I started this morning at 10am or so, got half an hour of work into it, mostly scanning the illustrations, and then I got sidetracked. A couple of carbon transfer prints to work on, a garden to tend to, having lunch with my significant other and working out plans for a brief vacation, some more carbon transfer work – and here we are, 3:30pm, finally ready to put some more work in. Oh no, actually not. Because the timer beeps on another carbon print that’s ready with its post-exposure soak, and I’ve got to mix some more glop so I can pour tissues tonight. BRB!

3:38pm – back to writing. Glop mix is blooming, and in the meantime I fixed a silly mistake in an HTML form for the carbon transfer database system I’ve built. I’m planning to do a blog on that as well, one of these days, so ignore it for now!

Anyway, as you can tell, I’ve been busy and much of it has actually been with printing. After months and months of mostly testing, I’ve not done much testing at all over the past few weeks, and instead I’ve just been churning out prints. That sounds like it has some kind of purpose, which of course it really doesn’t. But it still feels productive.

One of the things I’ve been working on is a portrait project shot on 8×10″ Fomapan 200 film and medium format Portra 400. The 8×10″ sheets are for…carbon prints of course! So I’ve been busy with those. I can’t share any imagery due to reasons of privacy, but it’s a massive learning curve for sure, and I’m really chuffed with how it’s proceeding. Not that it’s all flawless – far from it. It really is a learning curve. But at least it now seems I’m in control of the technique to the extent that I can drag some presentable prints from each portrait session.

What I can show you is some preliminary testing I did in anticipation of said portrait project. Here’s some:

These are all 4×5″ carbon prints from Fomapan 200 negatives. These were really just target practice. We had some interesting skies back in July (or late June?), so one time after dinner I head out and shot these over the course of 45 minutes or so. Those power lines always fascinate me and in this case, the skies formed a nice backdrop.

Most importantly, this gave me something to practice on, especially making silver gelatin negatives fit for DAS carbon transfer. The above negatives I intensified using chromium intensifier – one more thing I intend to do a blog post on one of these days. It’s a powerful technique, although sadly it uses nasty dichromate. But it’s just so darn effective for this purpose…

In retrospect, I might have intensified these negative a little more; they lack a bit of oomph even for the relatively high-pigment tissues I used for these prints. Not to worry – the test was a successful one in that it pretty much proved for me that I can more or less reliably get from scene to print using these materials and processes. Good!

So the next step was to scale it up to 8×10″ – after all, if it works for 4×5″, it should work for 8×10″ as well. Despite the significantly larger format, it’s not much more difficult to do at all. I made use of another summer evening to drive around with the Intrepid and a 300/5.6 Symmar-S a bit:

I saw this cloud formation with the setting sun breaking through as I was driving on the highway out of the village, so I quickly made my way to this spot with the row of poplars in the foreground and set up the shot. I made two negatives, but this one (the first) was really the superior one.

Another one, later that night:

Note the rough edge on this one at the top. That’s not as pretty as it could be, and indeed, it has led me to make two notable changes to my workflow.

If you look at the top right corner of the print above, you’ll see there’s a ragged corner and some grey bleed along the edge of the print. Ugh. This is because the film pipes some of the diffuse UV light onto the carbon tissue, and the notch on the sheet film tends to exaggerate the problem.

First, I switched to a different light source. The 8×10″ prints above I exposed with my trusty, old bank of Philips UV BL tubes. The 4×5″ prints I made with the dual wavelength LEDs I picked up from AliExpress some months ago, and made into a small 100W high intensity light source. LED has the advantage that the prints are just sharper, especially along the edges where a more diffuse light source will cause a lot of bleed/light piping, as shown above. The new light source is also one I intend to do a blog post on (and that makes three for the queue…), but to cut a long and future story short: it’s pretty much the same as the low-cost light source I used before.

The second change has to do with the edges themselves. I go through phases when it comes to printing the full frame, including rebates/margins. For a while, I really like including that black border (even though it makes every print look like a mourning card) and I print pretty much everything that way. And then at some point, I grow tired of it and I go back to printing just the image. To be honest, the border of sheet film is typically a bit wide to my taste, anyway. The resulting black edge is just too heavy, and it tends to weigh down on the composition substantially. So for the portrait project I’m doing now, I’m using a smaller rubylith mask that leaves out the film borders, printing just the image.

One more thing I’ve been working on, is spotting my prints. It’s something I never did before, but the initial batches of 8×10″ DAS carbon tended to have some small bubbles in them. Instead of reprinting anything with a bubble in it, I just gave spotting a try, and since then, I’ve been practicing on every print that needs it. It seems I’m getting good enough at it to at least obfuscate the most apparent problems sufficiently so that they don’t stand out too much!

My spotting tools. A little glass dish with a tiny amount of Winsor & Newton ‘Mars Black’ (iron oxide) watercolor paint on it, and a brush. Not pictured is a tiny cup of water. Simple tools for small problems!

Alright, one final thing. The prints above were all done with Kremer Pbk7 pigment – the dead-neutral black pigment I’ve been using a lot over the past few months. But as announced earlier, I’ve been trying Kremer’s XSL Black pigment recently. And I love it! It’s not as dead-neutral black as their powdered Pbk7 (even though XSL black is also Pbk7), but also not quite as warm as Talens India ink. It’s sort of in-between, and I find it works quite nicely for the portrait project, and many other monochrome prints as well.

The XSL stuff is so easy to work with! I just weigh it out, then dump it into the jar with the gelatin and sugar in there, add water and I’m on my way! No dispersants necessary, no lengthy tumbling or grinding – just add water and it turns into a perfect dispersion that’s every bit as good as India ink. Lovely!

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