Matte Black vs. Photo Black

[Jeremy]

I'm curious if anyone has done a study in terms of UV blocking power and/or smoothness of tones when using the matte black vs. photo black in making your digital negatives.

I know that many of you are using negatives which do not use an Black, but there are some of us who are

I personally am using photo black in my 2200 when making RGB digital negatives and as I am stepping up to an Epson 7600 I am curious about whether I should load pK or mK into the printer. My first thought was to go with pK as OHP is a rather glossy substrate and that has worked for me in the past (I also like printing on semi-gloss papers which take the pK ink), but after reading the QTR threads and checking out Reeder & Hinkel's website I see that they use mK in their Epson 4000 curve.

Any thoughts? Are the mK and pK interchangeable in terms of digital negatives or are they [yet] another variable?

 

[Ron-san]

I'm curious if anyone has done a study in terms of UV blocking power and/or smoothness of tones when using the matte black vs. photo black in making your digital negatives.

Any thoughts? Are the mK and pK interchangeable in terms of digital negatives or are they [yet] another variable?

Jeremy-- Here goes again. I messed up the earlier reply by hitting the wrong button.
In my experience the nearly the only property of an ink that matters when making digital negs is its ability to absorb (block) UV light. For the Ultrachrome inkset that the 7600 uses, either matte K or photo K ink is able, by itself, to print a patch dark enough result in pure white on a palladium emulsion. If you print so either the mK or pK ink is laid down along with the other colored inks you can easily get UV densities nearly up to 5.0 (all you need for pure white on palladium is a density of about 3.2). So either mK or pK works by that criteria.
Does any particular color of ink print more smooth tones than another? I really doubt it. When I look at a print through a loupe, all of the colored dots are of the same size -- so I expect all of the inks are equally "grainy" if the dots are blocking UV to the same extent. What makes for smooth tones is filling up the white holes around the dots as much as possible. For example, you could, in principle, print an entire grayscale with just the K ink, just spreading out the dots for the lighter tones. The result would be incredibly grainy, however. If you printed the entire grayscale with the K and LM inks the result would still look grainy since the LM ink absorbs so little light, even at 100%, that it is like printing with the K ink by itself.
There are several strategies for trying to achieve the smoothest tones but here is the one I like best. I set the K and LK inks to print the entire grayscale with the LK ink printing the lightest tones and then giving over to the K ink to print the darker tones. Then I set the other dark inks (C,M, and Y) to follow the distribution curve of the K ink. And I set the other light inks (LM and LC) to follow the distribution curve for the LK ink. In this way, at any given point in the grayscale, at least three inks are being printed. In the darker parts of the negative (which controls the critical light tones of the print) all seven inks are being used to some degree. This approach really fills in the holes and leads to very smooth negatives.
Whether this is the absolute best approach -- that is a matter for debate and experiment. But it is a good approach.
I use matte K ink because I like to print on matte papers when I am not making digital negatives and this saves switching inks. That is the only reason. Kevin Sullivan tells me that photo K actually makes a tougher negative, more resistant to scratches, and he like to use it for negs that will be manhandled by students. I find that with reasonable care my own negs are perfectly tough enough when printed with matte K.

Cheers, Ron-san

 

[Doyle Thomas]

I have been told by an Epson rep that the matte black K3 ink does not have the chemistry to adhere to transparency material well.

Kevin Sullivan tells me that photo K actually makes a tougher negative is true.

I find that with reasonable care my own negs are perfectly tough enough when printed with matte K. is also true.

Doyle

 

[dwross2]

I'll second the opinion that matte black K3 works perfectly well with Pictorico OHP. I make sure to let them dry and I either sleeve them between use or stack them with interleaving paper, but I've used some dozens of times comparison testing emulsions, and none seem the worse for wear.

The rep may have been referring to a different transparency film, or maybe (cynicism alert ) wants to encourage switching inks or owning two printers.

Denise

 

[sanking]

Jeremy-- If you print so either the mK or pK ink is laid down along with the other colored inks you can easily get UV densities nearly up to 5.0 (all you need for pure white on palladium is a density of about 3.2).
Cheers, Ron-san

I am curious how you are figuring the UV blocking density of 3.2 to print pure white in palladium? Are you actually measuring this with a UV densitometer? My experience, measuring with a UV densitometer, is that one gets pure white quite easily when the UV blocking density is around 2.2.

Sandy King

 

[Neil Poulsen]

I have been told by an Epson rep that the matte black K3 ink does not have the chemistry to adhere to transparency material well.Doyle

I have a pinhole problem on my 4000. I bought this printer in part, because I thought it would do a good job on digital negatives, and also because I wanted the larger size.

Big disappointment.

For one thing, I have a pinhole problem that I think is printer related. Some defects I think come from scratches in the material. But the pinholes tend to appear in one location, regardless of material orientation. To the point, when I use matte black, my pinhole count goes way up.

I've tried all different settings to resolve the issue, but to no avail. I'm thinking about getting the 3800 and dedicating it to digital negatives, using the 4000 for paper. Jeepers!

 

[Ron-san]

I am curious how you are figuring the UV blocking density of 3.2 to print pure white in palladium? Are you actually measuring this with a UV densitometer? My experience, measuring with a UV densitometer, is that one gets pure white quite easily when the UV blocking density is around 2.2.

Sandy King

Sandy--

I just found this old post that I had overlooked and never answered. I apologize for the oversight.
I have an Xrite 361T transmission densitometer which, as you know, can read in either visible light or in "UV" mode. Numerous times I have used it in the UV mode to read the transmission density of step wedge negative patches on either side of the patch that gives me pure white on a print. That is how I have come up with a number of about 3.2 for the UV density that gives pure white on a palladium print.
So, I am confidant of the reproducibility of my reading, as I am sure you are confidant about yours. How come we get readings that are 1 OD unit apart? Is my unit way out of calibration? I actually have no UV standard to calibrate it with but the unit works very well in the visible part of the spectrum (checking it against the calibration targets that came with the machine and with a Kodak 21 step wedge).
I routinely use lithium chloropalladite when I print in "pure" palladium. If I recall correctly, you use sodium chloropalladite. Is that the difference? Is one type of palladium salt giving a softer emulsion than the other?
I am going to be deeply embarassed if I have been blithely giving out an outrageously incorrect number, but better to find out earlier rather than later.

Cheers, Ron-san

 

[clay]

I have tested both sodium and lithium chloropalladate, and they give almost identical exposure scales. That said, there can be quite a bit of difference between papers. Some papers seem to be naturally more contrasty than others.

Another difference may be just in the approach to deciding what exactly is the maximum density needed to print pure white. At the top end of the scale, I don't rely on reflection density measurements from either scanners or reflection densitometers. I use my eyeball, which for the lighter tones is a far more sensitive instrument than anything commonly available to us. This approach was first mentioned to me by Dick Arentz many years ago, and while he is a big fan of using transmission densitometers for creating negatives, he maintains that for the lightest of tones, you should rely on the eye - and ideally with a print in hand made from a calibrated step tablet.

When I used this approach, I too was surprised to find that the maximum density that I wanted to print on my negative was quite a bit higher than what is commonly supposed. In order to have the faintest whisper of tone in the 95-100% values in a photoshop file, I found I needed to be printing a negative density of around 2.6 UV logD above the base density.

This surprised me a little, until I went back to the charts that Dick has in his book and lo-and-behold, if you look at the graphs, you will see that pure pd with no restrainer has a tremendously long print toe on it, and my results fit right in with what Dick had recorded earlier. If you look carefully at his charts, the 'nominal' ES of this process arbitrarily cuts off the the toe at a point that is above pure paper white.

This result came from using very fresh ferric oxalate, no restrainer, and fresh developer on COT320 paper.

So I guess I am agreeing with Ron. I find that using a net DR of 2.2 to be insufficient in getting the full benefit of the palladium toe on your print (without resorting to restrainers, which have a deleterious effect on the toe anyway)

Sandy--

I just found this old post that I had overlooked and never answered. I apologize for the oversight.
I have an Xrite 361T transmission densitometer which, as you know, can read in either visible light or in "UV" mode. Numerous times I have used it in the UV mode to read the transmission density of step wedge negative patches on either side of the patch that gives me pure white on a print. That is how I have come up with a number of about 3.2 for the UV density that gives pure white on a palladium print.
So, I am confidant of the reproducibility of my reading, as I am sure you are confidant about yours. How come we get readings that are 1 OD unit apart? Is my unit way out of calibration? I actually have no UV standard to calibrate it with but the unit works very well in the visible part of the spectrum (checking it against the calibration targets that came with the machine and with a Kodak 21 step wedge).
I routinely use lithium chloropalladite when I print in "pure" palladium. If I recall correctly, you use sodium chloropalladite. Is that the difference? Is one type of palladium salt giving a softer emulsion than the other?
I am going to be deeply embarassed if I have been blithely giving out an outrageously incorrect number, but better to find out earlier rather than later.

Cheers, Ron-san

 

[sanking]

Clay,

Interesting results. But Dick Arentz or otherwise I definitely don't find a tonal range that long in my own working conditions. I could quibble up to about 2.5 - 2.7, but beyond that I never see texture in the whites with pure palladium.

Sandy

 

[Ron-san]

Clay,

Interesting results. But Dick Arentz or otherwise I definitely don't find a tonal range that long in my own working conditions. I could quibble up to about 2.5 - 2.7, but beyond that I never see texture in the whites with pure palladium.

Sandy

Clay and Sandy--

I think I had better find a way to calibrate my UV densitometer before I continue this discussion. Looks like my reading are on the too high side compared to either of you.
I have standards for density measurements in the optical range for both reflectance and transmission modes (came with my Xrite 810). But does anyone have a suggestion where to get a good transmission density standard in the near UV, specifically the wavelengths that the Xrite 361T measures when in UV mode???

Ron-san

 

[sanking]

Clay and Sandy--

I think I had better find a way to calibrate my UV densitometer before I continue this discussion. Looks like my reading are on the too high side compared to either of you.
I have standards for density measurements in the optical range for both reflectance and transmission modes (came with my Xrite 810). But does anyone have a suggestion where to get a good transmission density standard in the near UV, specifically the wavelengths that the Xrite 361T measures when in UV mode???

Ron-san

When I originally asked the question I was not aware you were using DOP palladium. I get a much longer toinal range with the ammonim and lithium salts than with sodium, and especially when the humidity is very high, so an ES of 3.2 is definitely within the realm of possiibility.

Sandy

 

[Loris Medici]

Indeed, if you want maximum black you can get (while using digital negatives), even a 31-step tablet (>= log 3.1) is not enough (or barely enough) to get paper white with *POP* Palladium sensitizer... People often calibrate for 90% dmax when using in-camera negatives (no need for this with digital negatives; since you can use a curve to manipulate the negative densities) and IMO this greatly impacts the figures people use for comparing the DR they need for the process.

For the record, the DR I need for LiPd POP process is log 2.8 - 2.9 (as checked with a 31-step tablet)...

Regards,
Loris.

When I originally asked the question I was not aware you were using DOP palladium. I get a much longer tonal range with the ammonium and lithium salts than with sodium, and especially when the humidity is very high, so an ES of 3.2 is definitely within the realm of possibility.

Sandy

 

[Michael Mutmansky]

Clay,

Interesting results. But Dick Arentz or otherwise I definitely don't find a tonal range that long in my own working conditions. I could quibble up to about 2.5 - 2.7, but beyond that I never see texture in the whites with pure palladium.

Sandy

Then you might want to look at your base exposure and determine if you are getting a true maximum black.

If you plot an unrestrained curve for the full range of pt/pd (not the ES) it is much greater than 2.1, due to both the very long toe, and the 90% black cutoff.

My measurements coincide with Clay and Ron's. My negatives sound like they are matching up almost exactly with Ron's contrast range.


---Michael

 

[sanking]

My measurements coincide with Clay and Ron's. My negatives sound like they are matching up almost exactly with Ron's contrast range.


---Michael

Let me understand this. Are you saying that with DOP palladium (sodium chloride + ferric oxalate) your negatives need a UV density of log 3.2 to give paper white when exposure gives Dmax?

If so it proves there is no single ES that best describes palladium printing because I definitely get paper white with a UV density of 2.5 (or less) when exposure gives Dmax. This is at RH of about 55% and a 1:1 mixture of palladium chloride (15%) + ferric oxalate (20%). If I were to bump the humidity up to 70% or more, or substitute the ammonium or lithium salt, the scale would increase to 3.0 or more.

However, I have not found any reason to work at higher humidity since the Dmax I get at 55% by reflected reading is about log 1.50 or slightly higher (with COT 320). Are you and Clay getting significantly higher Dmax values than about 1.50?

One of the wild cards in this, other than humidity, is the condition of the ferric oxalate. Anything older than about 4-6 weeks ago starts to cause fog which may give a longer tonal scale so I always test with fresh FO.


Sandy King

 

[Michael Mutmansky]

Sandy,

I need to know more about your methods. Are you double coating? Using restrainer?

I never print over RH of 60%, and prefer it to be about 50%.

Using very fresh FO is a good thing, but most people aren't going to mix the night before, so you probably need to consider that when you discuss these values. It's probably better to be using a slightly aged FO for values that are going to be discussed on a forum like this, unless you are clear that they are fresh values, and what the will equate to in terms of aged FO.


Since we're talking about FO, the amount of OX acid in the FO can considerably affect the curve and speed as well. I suggest you look into that variable a bit too.


---Michael

 

[sanking]

Michael,

I typically print pure palladium with negatives that have DR of about 1.8-2.0, and I do use a small amount of dichromate restrainer with these negatives, about 1ml of a 5% potassium dichromate solution per liter of developer. I personally don't like the extreme highlight compression you get with very long scale palladium prints so I use the restrainer to drop the ES.

However, I have tested pure palladium (DOP) with no restrainer, at 55% RH and with the FO + PC solutions I mentioned earlier, and that is where I will get paper white with UV density of 2.5 or slightly less. I do test with fairly fresh ferric oxalate and I always add a bit of oxalic acid (about 5% by weight) when I first mix it. Then, I try to keep it fresh by storing in the refrigerator, or even freezer if I won't be using it for long periods of time. I have also added peroxide to the solution to re-freshen it, but for the most part I tend to mix the FO in small quantities and use it within 4-6 weeks to avoid the fog problem. I suppose if one stores the solution at room temperature and keeps it for a long time it might be best to test with slightly aged solution since the ES will definitely lengthen as the solution ages.

I don't usually double coat, but I will often do a first coating with plain distilled water, dry, and then coat with the FO + PC sensitizer.

On the whole I believe my method of printing DOP palladium is fairly typical and the only thing I can see that I may do differently from some people is to make sure that I am always working with very fresh FO.

With POP palladium, using ferric ammonium citrate and either the lithium or ammonium salt the tonal scale can indeed easily reach 3.2, or even longer in conditions of high humidity.

Sandy

 

[Ron-san]

Michael,



Sandy

Loris-- I believe your measurement, but I expect the numbers you quote are for density in the Optical part of the spectrum, not UV densities (since I expect your 31 step wedge is calibrated for optical, not UV density.

Michael and Sandy -- I am definitely getting the impression that relatively minor changes in protocol/chemistry can strongly affect the contrast range of a "pure" palladium emulsion. So maybe my UV densitometer is not so far out of whack after all.
For the record, I mix 3.5 grams of lithium chloride with 5 grams of palladium chloride in 50 ml of water. I then mix this one to one with a solution of 13 grams of ferric oxalate in 50 ml of water. I use reasonably fresh ferric oxalate solution(1-3 weeks old). I give a single, but quite heavy coat to Arches Platine paper, let it rest several minutes until the water sheen disappears, then hit it with the hair dryer. I have no idea what my relative humidity may be, but I bet it is near the Sahara desert. I go straight from the hair dryer to the Nuarc for exposure.
In judging pure white, I always place a piece of opaque plastic so it over laps the ) 0% patch of the step wedge. I assume the area under the plastic is pure white. Thus, even if my ferric oxalate is a bit off, I can assess how much UV density is needed to obtain a white that is the whitest a chemically coated piece of paper can give. When this patch is obviously not as white as uncoated paper, then I know the ferric oxalate needs to be remade.

I have found this discussion to be quite helpful and thank everyone who has chimed in.

Ron-san

 

[sanking]

L
Michael and Sandy -- I am definitely getting the impression that relatively minor changes in protocol/chemistry can strongly affect the contrast range of a "pure" palladium emulsion. So maybe my UV densitometer is not so far out of whack after all.
Ron-san

My experience is indeed that small changes in working conditions and chemistry can dramatically change the contrast range. Humidity is especially determinant in POP palladium with AFO and either the lithium or ammonium salt. But it can also play a big role in DOP palladium with FO + PC. I have printed DOP palladium in conditions of very high RH where exposure gave a printed out image almost as complete as one would expect with POP palladium.

I guess the question is, is there an optimum ES? And my answer to that is no, since it really depends on what kind of look you are going for. If you like the very long scale where the highlights just go on and on, then a very long ES is for you. I tend to like a slightly snappier print with less highlight compression. Whatever rocks your boat. The important thing is to understand that these differences do exist, and how to control them to our individual needs.



Sandy King

 

[Michael Mutmansky]

Sandy,

I think that in the context of digital negatives, the discussion of super long toes is somewhat misplaced, since the negative can be built so that the long toe is completely accommodated simply as a characteristic of the response curve of the printing process, and not a limitation or necessary characteristic of the final print. In other words, I build my negatives to match the monitor as well as possible. If the image has a long toe, so will the print, but if it doesn't, the print won't either.

This could very well be where the differences are coming from, IMO.


---Michael

 

[sanking]

Sandy,

I think that in the context of digital negatives, the discussion of super long toes is somewhat misplaced, since the negative can be built so that the long toe is completely accommodated simply as a characteristic of the response curve of the printing process, and not a limitation or necessary characteristic of the final print.

---Michael

Yes, I am aware of that, but my comments on that point were meant simply to address the issue of the advantages of a very long scale ES in general terms. In other words, is there any inherent advantage in printing palladium with a very long scale. I understand that there might be some advantages with in-camera negatives, but don't see any with digital negatives where, as you suggest, it is possible to strictly control linearity by adjusting your monitor.

However, I don't see how that explains the current discrepancy as to how much UV density is required to produce paper white in printing with pure palladium. My comments on this point have been entirely based on the use of digital negatives and building the negative in the same way you do. But it appears that for some reason your working procedures, and perhaps those of Clay and Ron, require more UV transmission density to get to paper white than do mine.

Since our observations must of necessity be based on actual reading of the negatives with a densitometer in UV mode, the issue may indeed simply be a difference in bandwidth transmission of our densitometers. My recollection is that you, Clay and Ron are using X-Rite densitometers, whereas I am using a Gretag D-200-II. Just for the record, the center wavelength of the UV transmission of the D-200-II is 373 nm, and the bandwidth is 33 nm in the maximum density range we are talking about.

Sandy

 

[clay]

I agree with the fact that you can linearize anything to make it look like the monitor. The main advantage I see to using the maximum scale that the palladium process has to offer is that you get the maximum warm tone and avoid any hint of graining.

As to your densitometer question - I don't really know. I am using an XRite 361T

In other words, is there any inherent advantage in printing palladium with a very long scale.
Sandy

 

[Michael Mutmansky]

As I see it, the longer the tonal scale, the more deliberate you must be to get a tonal change on the print. That reduces graining from the elimination of restrainer, and also from the inherent dot properties of the negative as well.

I don't know what the center point is of the x-Rite densitometer, but this could play a role in it some. Especially if you are printing colored negatives, as the colored inks are especially prone to what I call 'effective UV' density differences from the measured values. Epson blacks are not immune to that as well.



---Michael

 

[Kerik]

I'm with Clay and Michael on the scale issue. With both in-camera and digital negs my goal is to print palladium with very little or preferably no restrainer. One of the things that makes me scratch my head about the PDN system is the (IMO) insane amount of Na2 many users seem to employ, often using printers that I know can produce negs of appropriate DR for palladium with little or no Na2. I've had many workshop students show me prints from PDN negs with perfect distribution of step wedge tones but the prints are often gray and gritty rather than warm and smooth.

To get back to the original question, I use the photo black ink for digital negs with my 3800.

 

[Michael Mutmansky]

Original question? Crap, I forgot about that. I have my printer (4800) set up for Photo black, and that's how it's going to stay. Works great on the film I've used.


---Michael

 

[sanking]

I'm with Clay and Michael on the scale issue. With both in-camera and digital negs my goal is to print palladium with very little or preferably no restrainer. One of the things that makes me scratch my head about the PDN system is the (IMO) insane amount of Na2 many users seem to employ, often using printers that I know can produce negs of appropriate DR for palladium with little or no Na2. I've had many workshop students show me prints from PDN negs with perfect distribution of step wedge tones but the prints are often gray and gritty rather than warm and smooth.

To get back to the original question, I use the photo black ink for digital negs with my 3800.

Kerik,

Are you using just the photo black with the 3800, or are you adding in some other color? And are you using the Epson driver? When I tested the Epson 3800 with the Epson driver the photo black gave a maximum UV blocking density of about log 2.2. That is a far cry from the density of 3.2 that Ron noted that he needed to get paper white with palladium, which Clay and Michael appear to agree with.

Sandy