Pigments

[bob carnie]

I am going to do a workshop with my staff in the fall with The Pigment Hunter, first on our list is to be able to make the pigments we use daily for our gum prints . Then we may expand this workshop to explore Earth Pigments and techniques of grinding down to our specs, We use a lot of them here and also we can expand to staining our woods for framing which would be a secondary wormhole to go down.

Right now it CMY and a good Sepia that we are currently using is what we are tying to achieve with this workshop.

[Drew Wiley]

It's hell just finding a true black enamel. They might look black full strength, but betray something else if toned down a bit. One of the best came from Holland, and was especially expensive, but of no use in the context here because of the solvents and oil vehicle involved. But I mention this simply due to the fact that several different black pigments need to be combined to achieve a neutral result. Given the fact that some artist's pigments cost far more per volume, those manufacturers have more incentive to carefully combine ingredients.

[Ron McElroy]

I tried a French brand of lampblack watercolor (starts with an "S") that was very warm -- closer to what I have found with Ivory black. So there seems to be a variation in what lampblack actually is.

Some folks will add a little blue of some type to counter any warmth. I find Black Cat to be too warm (and glossy) on its own for me. But I have used Sumi ink in the past -- on its own (very warm, of course) but also to mix with lampblack to add a little warmth.

Sennelier?

[bob carnie]

It's hell just finding a true black enamel. They might look black full strength, but betray something else if toned down a bit. One of the best came from Holland, and was especially expensive, but of no use in the context here because of the solvents and oil vehicle involved. But I mention this simply due to the fact that several different black pigments need to be combined to achieve a neutral result. Given the fact that some artist's pigments cost far more per volume, those manufacturers have more incentive to carefully combine ingredients.

I have been mixing together c, m, y in equal amounts and get a very nice dark grey, I think finding a good black for gum printing is difficult, we will do a lot of testing on this, if you use the black as the first layer in the types of prints I make you can use a opaque pigment which opens the door for various possible pigments to use.

[Drew Wiley]

Yeah, gum is somewhat different. You'll probably need some kind of K printer opaque black for certain images, and it might need to be a blend. Wish I had an answer; but in my pigment background I had a relevant saying : there is never any such thing as pure white; nor is there any such thing as real black. The eye has to be fooled into thinking it so via sheer saturation, or by offsetting one hue bias with another. Black is the Achilles heel of inkjet printing.

[koraks]

I do have a probably easy question concerning pigments for B&W carbon transfer. I'm looking for a good neutral to cool black pigment, preferably already dispersed, so something like watercolor paint or whathaveyou.

To answer my own question: it turns out that Kremer Furnace Black Pbk7 (which is essentially the same as 'lamp black' AFAIK) is a very neutral pigment of a fine grind and high tinting strength: https://www.kremer-pigmente.com/en/s...47250-furnace-
black.html
It's a powdered pigment so needs to be dispersed, but since posting my question back then I got into using dried pigments and have figured out (I think) how to make a decent quality dispersion, provided the pigment is of good quality, esp. uniform and small particle size.
I have yet to try Kremer's XSL black, which is essentially the same pigment, but bound to a vehicle that should make it easy to disperse by simply stirring the tiny pellets in water. https://www.kremer-pigmente.com/en/s...xsl-black.html


Here's a quick 4x5 I made with the Kremer Pbk7. The tissue is a 0.25% Pbk7 and 8% gelatin (so ca. 0.31g pigment per 10g gelatin), which already gives a rather high contrast. I think a more reasonable loading would be around 0.1g pigment per 10g gelatin.

[bob carnie]

I am interested in the permanence values of pigment that I use, Right now I am using The Wet Print and Daniel Smith.. The wet print pigments are rated Blue Wool Scale of 8 - which is suppose to be pretty good, I am not sure what the BWS rating is for Daniel Smith. they just say on the packaging High Permanence, transparent, low stain, and low granularity, It took me a long time looking at all their charts to come up with a good set of tri colour pigments, I had to mix equal Green and Blue to get my cyan to be of the same qualities of the yellow and magenta.

We as photographers are a funny breed where some of us are obsessed to colour permanence, I think in part a lot of us are old enough to remember the pain of fading C prints (dye coupler).. This obsession with permanence does not seem to be the case with painters.
I am wondering if some of you have links to references of the relative merits of different pigments . Permanence Levels - Opacity to Transmission Levels- Staining Levels and of course Granularity.

Right now I am stuck at Blue Wool Scale - and wondering if anyone has gone further down this wormhole....

Drew I do know you invented photography in the High Sierras with Bigfoot in the caves where you ground pigments together, it amazes me that Nicephore Niepce visited you in the 1800's and even more that you are actually that old but I am looking for some real world info that can lead me to the right answers to my needs.

thanks in advance.

[koraks]

Bob, the best I can offer is something you probably already know about; the excellent overview of pigments compiled by Bruce MacEvoy at handprint.com; follow this one for the pigment index: https://www.handprint.com/HP/WCL/palette1.html It's conveniently grouped by color and within that on pigment code. You'll find the pigments in your Daniel Smith paint listed on the tube. He lists blue-wool scale ratings (not sure what source is he used) combined with his own testing (which he has done for a surprising number of pigments).

There's also this very comprehensive and easily accessible pigment database: http://www.artiscreation.com/Color_index_names.html
It consists of information compiled from several sources, including handprint.com, so to an extent it's redundant - but more comprehensive as it lists some pigments that handprint.com doesn't.

However, when it comes to permanence, I fear that figuring out how well your pigments will fare is a tricky proposition at best. The ratings provided by manufacturers or independent parties will give an indication, but if I look at the inconsistenties in some cases between for instance MacEvoy's findings and the industry-supplied ratings, it's clear that there are many nuances. Then there's the issue that a pigment of the same code (let's say PR122 or PB15:3) can differ between manufacturers, and as a consumer you never know what kind of differences there are - or even where the pigment you're using actually comes from. Relevant differences might be particle size or subtle chemical differences/impurities that can have an impact on the chemical stability of the pigment.

To make matters worse, sometimes, characteristics can be a blessing and a curse at the same time. For instance smaller particle size will generally result in higher tinting strength and higher chroma, but will also make the pigment more sensitive to chemical attack and hence fading, darkening or chroma loss.

I can imagine that further complications come from the way the pigment is used; there can be advantages (a matrix like gum or gelatin might protect the pigment locked inside of it) or disadvantages (traces of dichromate or other chemicals may form a threat to long-term stability). Long story short; it seems that the advice given by people like MacEvoy to do your own testing is probably not just a luxury, but an actual necessity if you want to determine if the pigments you, specifically, are using are sufficiently lightfast. I don't take it that far and just hope for the best based on the data I can find online.

That the lightfastness issue is hairy business is demonstrated by the change in yellow that Calvin Grier (thewetprint.com) recently implemented. He used PY155 earlier, a benzimidazole yellow, but apparently his own testing proved that this wasn't as lightfast as the PY184 he is now using (or at least retailing) in his pastes. I don't doubt that the PY155 had excellent lightfastness ratings according to the manufacturer, otherwise I bet Calvin would have eliminated in earlier assays, but apparently his own testing proved otherwise.

It's a wormhole for sure, and I'm afraid there's no easy answer. There isn't even a complicated one that comes quickly - it appears the only real answer is a long and complicated one that takes a long time to arrive at.

Concerning your cyan: your blue & green mix sounds interesting. What problem were you trying to solve? For cyan so far I'm just using PB15:3 just like Calvin does and while I had some trouble before with it being on the blue side, I now seem to be hitting the same hue angle he does with his pigments, which is assuring. At least, if the pigment is properly dispersed and processed, which took me a week or two to figure out and resolve. I also find that in the pigment set I'm using (currently PB15:3, PR122 and PY154), the cyan PB15:3 actually has the highest tinting strength. I haven't looked into green pigments much yet, but if memory serves virtually all of the stable ones have lower chroma than PB15:3, so using a convenience mix of blue + green would logically not help all that much in realizing a larger gamut. Or am I mistaken?

[Vaughn]

Good you have found a good black! I have stayed away from using dry pigments...too lazy (and very happy with what I am using).

It is almost impossible to compare pigment loading of different pigment types usefully. I use 5 grams of Grahams lampblack per 750ml of water, which is 0.7%...ca 0.6 grams pigment per 10 grams of gelatin. The weight of my pigment also includes the binder (gum arabic, water and honey) and thus the tissue is very low contrast.

[bob carnie]

Bob, the best I can offer is something you probably already know about; the excellent overview of pigments compiled by Bruce MacEvoy at handprint.com; follow this one for the pigment index: https://www.handprint.com/HP/WCL/palette1.html It's conveniently grouped by color and within that on pigment code. You'll find the pigments in your Daniel Smith paint listed on the tube. He lists blue-wool scale ratings (not sure what source is he used) combined with his own testing (which he has done for a surprising number of pigments).

There's also this very comprehensive and easily accessible pigment database: http://www.artiscreation.com/Color_index_names.html
It consists of information compiled from several sources, including handprint.com, so to an extent it's redundant - but more comprehensive as it lists some pigments that handprint.com doesn't.

However, when it comes to permanence, I fear that figuring out how well your pigments will fare is a tricky proposition at best. The ratings provided by manufacturers or independent parties will give an indication, but if I look at the inconsistenties in some cases between for instance MacEvoy's findings and the industry-supplied ratings, it's clear that there are many nuances. Then there's the issue that a pigment of the same code (let's say PR122 or PB15:3) can differ between manufacturers, and as a consumer you never know what kind of differences there are - or even where the pigment you're using actually comes from. Relevant differences might be particle size or subtle chemical differences/impurities that can have an impact on the chemical stability of the pigment.

To make matters worse, sometimes, characteristics can be a blessing and a curse at the same time. For instance smaller particle size will generally result in higher tinting strength and higher chroma, but will also make the pigment more sensitive to chemical attack and hence fading, darkening or chroma loss.

I can imagine that further complications come from the way the pigment is used; there can be advantages (a matrix like gum or gelatin might protect the pigment locked inside of it) or disadvantages (traces of dichromate or other chemicals may form a threat to long-term stability). Long story short; it seems that the advice given by people like MacEvoy to do your own testing is probably not just a luxury, but an actual necessity if you want to determine if the pigments you, specifically, are using are sufficiently lightfast. I don't take it that far and just hope for the best based on the data I can find online.

That the lightfastness issue is hairy business is demonstrated by the change in yellow that Calvin Grier (thewetprint.com) recently implemented. He used PY155 earlier, a benzimidazole yellow, but apparently his own testing proved that this wasn't as lightfast as the PY184 he is now using (or at least retailing) in his pastes. I don't doubt that the PY155 had excellent lightfastness ratings according to the manufacturer, otherwise I bet Calvin would have eliminated in earlier assays, but apparently his own testing proved otherwise.

It's a wormhole for sure, and I'm afraid there's no easy answer. There isn't even a complicated one that comes quickly - it appears the only real answer is a long and complicated one that takes a long time to arrive at.

Concerning your cyan: your blue & green mix sounds interesting. What problem were you trying to solve? For cyan so far I'm just using PB15:3 just like Calvin does and while I had some trouble before with it being on the blue side, I now seem to be hitting the same hue angle he does with his pigments, which is assuring. At least, if the pigment is properly dispersed and processed, which took me a week or two to figure out and resolve. I also find that in the pigment set I'm using (currently PB15:3, PR122 and PY154), the cyan PB15:3 actually has the highest tinting strength. I haven't looked into green pigments much yet, but if memory serves virtually all of the stable ones have lower chroma than PB15:3, so using a convenience mix of blue + green would logically not help all that much in realizing a larger gamut. Or am I mistaken?

Hi Koraks

thanks so much I will look into Bruce MacEvoy as you list.
I do plan some tests myself to leave pigments in the outdoors for months on end and do LAB readings at time of printing and over time to see which of the pigments I use lose density.
I hope that the dichromates are removed with the wash process, as well one can do a metabisulfite bath at the end but I have no idea how to read the levels of AD in my finished gum prints
I use Calvins Cyan now , I am talking pre The Wet Print , Christina A and others recommended Thaylo Blue Green shade for cyan but it is a high staining pigment so I started custom mixing Viridian Green with a blue to get my cyan.
It was a PIA and am very happy with Calvins.

On a FB Gum page I have seen people use many types of colourant to make the colour and I think they have good possibilities.


Bob