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!

The go-to pigment source for carbon transfer printing these days is probably India ink. Sandy King et al. recommend Speedball or Black Cat India ink. Being Europe-based, I’ve tried neither, so can’t comment, but I suspect these are on the warm side of the spectrum as well, at least going by the example prints as reproduced in the cited book.

When I just started carbon transfer, a couple of years ago, I bought some ink here and there, and quickly found not everything works as it should. For instance, I picked up a small bottle of ‘Colorall’ India ink, which seemed to have a very nice purple-black hue that I really liked a lot! Turned out that the purple tone was due to one or more dyes added to the ink, and the dyes would simply soak into the final transfer paper, coloring all whites and highlights as well as the print borders this nice shade of purple. Ehmm…no, thanks. Lesson learned: dyes don’t work for single-transfer carbon. (At this point, having done a bit of double-transfer, I suspect it might be possible to make them work in that scenario, but so far haven’t bothered to try).

The more successful product I did stumble across back then is Talens India Ink. It immediately became my go-to ink and as such I have used it extensively. Only recently I found it also happens to be recommended by Calvin Grier for carbon transfer printing. I’m not the only one to appreciate its qualities!

The Talens ink really is great stuff. Place a drop into a beaker of water and it clouds out very nicely, demonstrating its excellent dispersion and fine grind. It’s also very stable; I bought a bottle of the stuff a couple of years ago and have been using it since with no signs of clumping or deterioration. And if you’re into it, it gives a very rich, warm black that leans distinctly towards sepia. Indeed, for many images, this works great. Just not for all of them. So despite its technical superiority, the Talens ink isn’t the ultimate solution for all instances, for me. Sometimes, I want something more neutral, or even cool-toned.

So what’s a guy to do? I tried the obvious things, like adding a bit of color paint (acrylic or watercolor) to shift the hue in the desired direction. A bit of blue and a tinge of red added to the Talens base can produce a very nice hue indeed, and evidently, there’s an infinite number of hues one could produce this way. But getting a dead-neutral black is challenging, and in a way, it also feels like the adage “two wrongs don’t make a right” – it’s fixing a hue problem by introducing a deliberate hue problem and then try to make them cancel out. Look, there’s nothing wrong with this and it’s a perfectly workable solution. But still, are there other ways?

Evidently, getting a neutral carbon black would be the obvious way to go. One way that works quite well is an acrylic paint also from Talens, sold under the ‘Amsterdam’ brand: #735 oxide black. It’s an iron oxide black and in my experience it’s near-neutral in hue, with a slight tendency towards green. That’s unfortunate, because I don’t really like a greenish tint to B&W prints (this is why I selenium tone most of my B&W silver gelatin prints). There are other drawbacks as well. Iron oxide is pretty darn difficult to disperse well, and although the Amsterdam acrylic is actually a rather good product in this sense, the pigment still has a tendency to settle to the bottom of the jar when leaving a hot glop to degas.

Some of the blacks I’ve tried so far for carbon transfer.

I’ve actually tried other sources of black iron oxide, such as a dry pigment from Kremer and also Winsor & Newton Mars Black watercolor, but both options were disappointing compared to the Amsterdam acrylic paint: in both cases, the pigment was far too coarse to have decent tinting strength and the quality of the dispersions was poor (in the Winsor watercolor) to downright abysmal (the dry pigment).

Furthermore, black iron oxide is magnetic, so using e.g. a magnetic stirrer to dilute some paint results in the interesting phenomenon of all the pigment sticking either pole of the stirrer bar, leaving the liquid almost clear! Any magnetic, however weak (including our planet!) will make the iron oxide pigment concentrate in a single spot.

Without being particularly systematic about it, I from time to time keep purchasing some black pigment (or paint) if I come across it, just to see how it performs and if it’s an interesting option for my printing. The benefit is that black pigments are generally quite affordable, so there’s little penalty to a failed experiment.

As a result, I picked up some Ivory/Bone Black from Verfmolen De Kat. It was actually in the shelves of my local arts supplies store, so I thought I’d give it a go. While it may work very nicely for things like oil painting, acrylics and other applications where there’s a high pigment concentration in a high-viscosity binder, it turned out to be absolutely hopeless for carbon transfer. The grind is far too coarse and even a concentration of 1% dry pigment to 8% gelatin struggled to produce much contrast and a true black. On the upshot, the tone is pretty neutral, so it has that going for it. But I generally don’t like working with too coarse pigments, as they don’t disperse very easily, and this bone black is no exception. When mixed into a glop, the glop needs to be thoroughly stirred before pouring to get the lazy pigment to depart from the bottle where it will inevitably have all settled by the time you’re ready to pour your tissues. The coarse grind also makes for a somewhat coarse/grainy image structure, which I don’t particularly care for mostly.

And then I stumbled across this one, from Kremer pigments: a plain and simple Furnace Black (which I understand is the same as lamp black, technically), pigment code Pbk7. It’s cheap. It’s cheerful. It’s incredibly finely ground – probably because it isn’t ground in the first place, but because the manufacturing process (which essentially consists of burning oil in a controlled way) creates a very finely divided, well, soot basically, which is then collected and probably sieved. Alright, it makes a royal mess if you try and pour the contents of the bag of dry pigment into a jar, there’s some fine carbon dust that’s being thrown up and I bet it’s not healthy to breathe it in (it did give me a nasty headache!) Oh, did I mention the mess it makes? Ye lords. Black everywhere!

Dispersion assay: Bone black Pbk9 to the left, Kremer Furnace Black Pbk7 to the right. Note how nice it clouds out!

But boy, is this a nice pigment to work with. It disperses very nicely with a few drops of Orotan 731 and has insanely high tinting strength. I haven’t tested it side by side with the Talens India ink yet, but I bet the tinting strength is in the same league as that of the pigment in the Talens ink. Of course, the dry pigment is more concentrated (at 100%, duh!), so it takes even less of the dry pigment than of an India ink to get the same optical density. I tried a first batch of tissues with 0nly 0.25% w/v of the Pbk7 pigment to 8% gelatin, and it seems to me this is in the same ballpark as around 2-3% of Talens India ink. I guesstimate a loading of around 0.1g Pbk7 to 10g gelatin would be appropriate for long-tonal scale carbon negatives and prints with decent contrast, similar to a 1% India ink loading in a 8% gelatin glop.

And it’s so nicely neutral in hue. It tends a bit to the cool side, it seems, which is just what I was looking for! Here’s a test print I just made, hanging to dry:

Test print made with Kremer Pbk7 Furnace Black, 0.25% w/v pigment to 8% w/v gelatin. 0.5ml 4% ammonium dichromate sensitizer to 12x15cm tissue, exposure 6 minutes under strong UV LEDs.

This pigment is just gorgeous, it really is. The drawback is that it’s a dry one, so it needs to be dispersed before it can be used. I’m using a very basic rock tumbler for this, but a paint muller would work as well for small batches. What I haven’t tried yet, but seems promising, is the easy-to-use (supposedly) XSL Black again by Kremer, which is the same pigment, but processed as pellets together with a dispersion agent. Apparently, you can just dump these pellets into water, stir, and they will ‘dissolve’ (disperse) without much work or addition of any other ingredients. Sounds great!

In any case, I’m sure I’ll be enjoying this new discovery of mine – which of course happens to be just about the oldest black pigment in common use. Sometimes, the old stuff really is the best. But I’ve got to say, the Kremer product does seem very hard to beat. It really is a top-notch rendition of a classic.

2 thoughts on “Black is the new black – Pigments for B&W carbon transfer”

    1. Primarily visually indeed, because what matters most, in the end, is how it looks! But since recently I’ve also been using an xRite i1 Pro for color measurements.

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