I will verify the film in bit.
This is really embarrassing… I was 100% sure it was an ultra Premium… Just found an old receipt, it says “Premium”
Will order correct film right now. Do you think it will cure all the issues?
Really sorry for the confusion.
It may cure them. (fingers crossed). I can’t tell for sure so I don’t want to say everything will be ok. However, many other people have great success with PREMIUM OHP and the curves/workflow you are doing so it’s certainly not that. Generally, once the workflow is validated, these things fall into three categories: a material issue (not the same paper), an ink switch issue, or a funky printer issue. If it was an ink issue or some fundamental flaw in the software, everyone would have the same problem and would be clamoring about it full-tilt.
regards,
hope OHP Ultra Prem. works,
Walker
Hello!
Here is an update:
Got Pictorico Ultra today, run more tests. You can definitely see the difference in the way film takes up on ink - more smooth, beautiful tones, even in 100% black.
Run both 8 ink calibration file and 21 step. Did not see much difference, but definitely got better, more smooth gradations. Run “real life” file in 1.4 , 1.6 and 1.8 curves. The contrast of 1.8 curve looks the best. 50% tones were a little heavy. Made a simple Ps correction curve, re-run file under 1.8 curve, looks fantastic! you know, even after all these years, it never cease to amaze me how well piezography system renders extreme shadows and extreme highlights! Now, if this would be my final product, I would be a happy camper. Problem is, I still measure 100%black at 2.89, with the clear at 0.19, I understand, my old xrite810 might be off, but still, the difference! With Meth3 1.4 profile, I measure 1.97 for 100% black.
Again, I intend to run negatives for Platinum/Palladium and positives for Copper Photogravure. For copper, I should stay around 1.2 to 1.4 Dmax, is there a way for me to keep great contrast I am getting from 1.8 curve printing (with small adjustment curve)? Should I use this extreme output for Platinum negatives and be happy? Can it handle this fantastic dmax?
If I need a custom curve, I will be happy to mail you a target file and pay for calculations.
Please let me know,
Sergey
Pt/Pd can handle a density range of 2.0 max…
Your densitometer is just not accurate right now.
No use relying on something that is not giving you useful information back.
So, I would not worry about it - and just make some film and make a Pt/Pd print.
Choose a chemistry/paper/coating/developer combo
Coat and dry some paper.
Find your optimum exposure by step exposing through clear OHP film - evaluate after drying the print.
Then print a black square with each of the 1.4, 1.5, 1.6, 1.7 and 1.8 density curves and expose at your optimum exposure.
See which density curve gives you specular white or just a tad of tone white (your preference).
You may even favor a white with lots of tone. So this is your choice. Which ever curve gives you the DR you prefer.
Then you have the correct exposure and density range.
Usually it is the 1.7 or 1.8 curve. But its still a good exercise to see them all.
Then all is left to do is build a contrast adjustment (correction) curve for PS to compensate for your chemistry/paper/coating/developer combo.
Then go forth and make prints!
If you can get the Pt/Pd going and print full range with the 1.7 or 1.8 curve, that should convince you that your densitometer is off and the system is running correctly.
Try the 1.4 for the gravure. If you need, I can make you a 1.20 and 1.30 curve.
best,
jon
Thank you so much for an advice, Jon! I will follow it with Pt/Pd
As for the gravure, my etching would be so much easier if I stay within 1.2!
If I can get a curve that “opens up” shadows at 80% to 95% grey range and gives me good densities at 5% to 15% greys, I would be in heaven. Extreme blacks and lights are most difficult to etch.
Please let me know if I need to run any target here for a curve creation.
Thank you so much!
Sergey
Jon!
I agree that my densitometer is off in absolute numbers. But I can still use it for comparison evaluation. My 21step file printed using 1.4 curve shows density that corresponds to step 13 on 2115 Stouffer scale.
Maybe, if you have a 1.20 curve, I will be at step 11, which is where I would like to be for gravure.
Sorry to bother you, I am usually not spending so much time for calibration issues, but since my photogravure students are asking, and, since I am a strong advocate of your system, I want to be comfortable to recommend it and being able to substantiate my workflow decisions.
Thank you,
Sergey Zlotnikov
A little clarification: the reason I am asking for 1.2 curve is that in my understanding of the process, it will limit the printer to produce densities not to exceed step 11(approximately) from the stouffer scale, while giving the full range of tones within these parameters. On the contrary, if I will be using 1.4 curve and artificially move black point in Photoshop to reduce max density, I will be only using part of the grey spectrum, limiting the richness of the system. Maybe I am wrong.
Jon!
After conversations with Walker I got confirmation from him that most likely the reason for my problems printing correctly lies with the printer itself. After Walker received and examined my printouts, his opinion (and I agree with him) is that printer misinterprets one (or more) channels.
It is not the ink, or profile, or my preparing of files, or film.
This leave me with two options, (short of buying new printer) - to try to create a new quad profile myself, or order one at your lab and pay for it.
I would rather order custom profile with your specialists, if it is possible.
I started to create my own profile on XP machine and regular QTRip, but it will take a long time and will not be as good as yours.
Please let me know how should I proceed.
Thank you so much, appreciate the help,
Sergey Zlotnikov
btw, I followed your advise and tried Colortac adhesive tissue for temporarily mounting paper on aluminum plate for duotone platinum printing, and it worked great on my Drytac HGP 220 press. I was very impressed that when re-heated, paper wuld separate from adhesive cleanly! Thank you so much for this advice! Below is the first test for tritone print using pt/pd
Profiling for darkroom negatives is actually something that is exponentially more complex than for normal Piezography printing and our original profiler was never built for it. We actually DON’T offer customer negative profiles. We offer baselines that can be calibrated with photoshop curves. This is still easier than PDN but not ideal.
I’m developing a tool in-house that can let us do this but it’s still a way off.
Building a personal baseline (manual curve creation) would take weeks. Every baseline curve (meth3v6 for example) takes hundreds and hundreds of hours worth of iterative work.
Again, we are developing a more streamlined system but I can’t comment until it’s done.
Walker
Ok, I was referring to an item on your website that says “custom ICC profile” but what you are saying it works only with color inks? And my only option at this point is to build custom quad file myself, using a function in QTRip software? Short of buying another printer. Would you suggest channels from the printout you have from me, as candidates for building new set? I understand the part of calibrating output in Photoshop using curves, I just want to start with “normal” looking 21step file. You have seen mine, the tonalities there are shifted, right? I would appreciate the advice.
From the printouts you have seen, 1.4, 1.6, 1.8, do you think I should be able to correct it with Photoshop curves only?
I think you can do it with photoshop. It’s printing true 16bit so you have 65,000 tones to choose from (as apposed to 256 in 8bit Grayscale or with inferior ink systems). As I mentioned by email, compressing your highlights (in this case bring your Shadows up in Photoshop) will not decrease image quality!
Walker
OK, I will try this, thank you!
What dMax did you end up with for the Pt/Pd print?
My best guess, 1.55… (we do know that my densitometer is off, and Xrite enamel target is supposed to be 1.8, but it measures 2.0 and I took off 0.20 from the measurement of 1.75, to arrive at 1.55 for my shadows)
I was not shooting for really high dmax, the objective of this test was registration, adhesion, paper separation at the end of the cycle, general sense of coming up with individual films. The image is definitely not the best for duotone, let along tritone. It is just I was so excited that your advice worked (dry mount tissue choice) that I had to try something fast. Moreover, I am waiting for a new set of pt pd salts, classic, no Na2, so I will have to do completely new set of calibrations. I realized that if I am to employ this duotone techique I have to be extra careful really clearing off any traces of Fe oxalate after development, it builds up fast. What are you using as clearing agent?
Sounds fantastic.
My clearing bath is quite simple: 1000ml Water, 25ml Perma Wash, 55gms EDTA. With hot Potassium Oxalate developer, I find the prints nearly clear themselves during development. Then I go to hot water baths, then finally to the clearing bath for 5 minutes. You can also do one hot water bath, followed by two clearing baths. For me it is best to use less chemicals so I can use less final water rinse to clear the clearing agents.
We are producing our own Palladium and Platinum solutions from extremely pure metal catalysts. So, look for these on InkjetMall shortly. We will be supplying all kinds of alternative process materials shortly. For the metals we will have sample sizes so you can test before investing. These should be online with two weeks. We will also be distributing Berger, the new Hanhemuhle Platinum (which is really very good), Pictorico film, and coating supplies, etc.
Thank you so much for detailed advice! How hot do you make your developer/ hot water baths?
i will definitely try your pt/pd supplies when they are available… As well as Hanhemuhle.
speaking of papers, I will run some tests washing papers I like in oxillic acid and seeing if they become suitable for pt/pd
Also, I am in the middle next test, using really thin 13gram gumpi mounted with colortac tissue, to see how it prints and separates. It takes platinum fantastically, it is the coating that is impossible, but mounted it looks stable to receive emulsion… we will see.
Potassium Oxalate at 140ƒ. Hotter is warmer and better dMax.
How water bath at about 120ƒ
I have some of the Hakkinishi Tosa thin gampi. Really difficult to handle but it takes to printing beautifully. Let me know if you come up with a solution for working with it!
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