Re: Using Epson Matte Black instead of Piezography Ultra HD Matte
If you can take a higher loss of density, PK ink has much better performance on?abrasion resistance. Or you can mix Epson PK and Piezography UHD MK in a ratio been tested on your paper, to recovery some density and keep the resistance?performance. And I mean using the QTR curve to control it, not mixing them in a bottle?physically.
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Kang-Wei Hsu
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Effect of Fixatives on Inkjet Papers Preservation and Imaging Quality
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Re: Just starting out with QTR
OK this makes sense to me. However, where do I get expected densities? When I look at the output (GRAY_CURVE) from "BWMASTERY-21-step-QTR-Correction-Curve-Tool-for-Digital-Negatives", it looks like something different is going on. The first value of the pair is as you suggest the excepted value taken from the step tablet (0 to 100 in steps of 5). The second number is something altogether different. it is neither the expected nor the measured, but some correction factor. If I make a plot of the output pairs from the excel sheet, it looks like a mirror image of the original measured densities. Presumably, when applied this correction factor moves the measured densities onto the ideal straight line between 0;0 and 100;100. This sheet is designed to output a GRAY_CURVE for negatives, the principle should be the same if the curve is for a positive print to paper...I'm just not sure what to make of this correction factor...
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Re: Using Epson Matte Black instead of Piezography Ultra HD Matte
Epson MK will work just fine. Slight loss of dmax but no need to recalibrate
best, Walker
Hi,
New to the forum. I would normally post this over on the Piezography forum but it's down at the moment and I imagine plenty of you over here will have experience of piezography. Plus I'd thought about dipping my toe in these here waters anyway :)
Has anyone ever tried using official Epson matte black in place of Piezography ultra HD matte black ink? While still using the other Piezography dark, medium and light gray inks, as well as the PIezography Pro linearisation tools.
Roughly speaking, would this work? I envisage some hit to dmax, but that's fine, this is for printing hand made zines and books and so dmax isn't as much a concern as it is for when I make wall prints on fancier papers.
I have a "Piezography Pro" setup on a 3880 and a R3000. I am only using 7 channels on each as I never print gloss/photo black, so my thinking is I would just use one of the two spare channels on each printer for an Epson matte black cartridge. Keeping the Piezography ultra HD matte black cartridge in place for when I make prints.
Why would I do this you ask? Until investing in my piezography setup I had no idea quite how unstable Piezography matte black can be on the surface of the paper compared to Epson matte black. On many papers, the mearest light touch can easily smudge the Piezography matte black ink. Not such a problem for wall prints, but definitely an issue for zines and books. For my first book made using piezography inks () I got around this by using a spray fixative (I found Permajet PermaSeal the best) and really reducing the ink limit as much as possible while still getting a satisfactory dmax. However spraying each page was loooong, not to mention smelly. When printing on the same papers using standard Epson inks the result is vastly more stable to touch.
I do have a P600 still running Epson inks, which I use for colour work, however I predominantly work in BW and I want to keep the Piezography workflow which I have found so precise and efficient for trialling and optimising papers that I may use in my books and zines, not to mention the toning, which I find lifts the end result above what I have ever been able to achieve with Epson inks.
Cheers,
Chris.
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Re: Just starting out with QTR
GRAY_CURVE has pairs of numbers - in each pair, the first number is the expected density, and the second number is the actual (measured) density. The expected densities go from 0 to 100. Measured densities can, I believe, be in any monotonically-increasing units. ? Example: both the expected and the actual 0 density were the same 0 value. Next value, I printed out a gray value of 5% but when I measured it it was 11%. Third one, I printed out 10% but it measured as 19%.? So, my GRAY_CURVE might start out GRAY_CURVE=“0;0 ?5;11 ? 10;19 ? [and so on until the end of the curve…] ?95;70 ?100;72"
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I managed to create a warm curve for Canson Arches 88 paper on my P-800. The process worked out better than I expected. The 21-step target printed almost perfectly linear (using LINEARIZE with Data-Tool). I started with the warm because it did not require toner inks. I have to say that the tone of the black inks alone is not to my liking at all :) I'll be working on the other curves this week.
The new problem has to do with Gray_Curve. I think this is an important tool in the arsenal to get linear curves and I would like to experiment. The document "Quad Ink Descriptor File Format?Specification For QuadToneRIP 2.8" is a godsend for learning the ins and outs of the ink descriptor file. However, the format for the Gray_Curve key still has me puzzled. I get the overall format but not "input-output coordinates." It appears from the description I can use density measurements but I'm not sure if they are the input or output, and what's the other number? I tried with the %lightness of the 21-step target as the "other" and get crazy non-linear results...Thanks for your continued support with this.
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Re: Just starting out with QTR
I managed to create a warm curve for Canson Arches 88 paper on my P-800. The process worked out better than I expected. The 21-step target printed almost perfectly linear (using LINEARIZE with Data-Tool). I started with the warm because it did not require toner inks. I have to say that the tone of the black inks alone is not to my liking at all :) I'll be working on the other curves this week.
The new problem has to do with Gray_Curve. I think this is an important tool in the arsenal to get linear curves and I would like to experiment. The document "Quad Ink Descriptor File Format?Specification For QuadToneRIP 2.8" is a godsend for learning the ins and outs of the ink descriptor file. However, the format for the Gray_Curve key still has me puzzled. I get the overall format but not "input-output coordinates." It appears from the description I can use density measurements but I'm not sure if they are the input or output, and what's the other number? I tried with the %lightness of the 21-step target as the "other" and get crazy non-linear results...Thanks for your continued support with this.
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Re: Using Epson Matte Black instead of Piezography Ultra HD Matte
Hi Paul, I have been interested in your recipes/approach. Particularly in regards to this 'touch stability' issue (please correct me if there's a better term to use), so I'm glad you chipped in.
How stable is the STS ink to touch?
And are you saying the STS formulation is similar or the same as Epson matt black? Apologies if not, that's what I'm inferring from your reply.
Cheers,
Chris.
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Re: Using Epson Matte Black instead of Piezography Ultra HD Matte
...?I had no idea quite how unstable Piezography matte black can be on the surface of the paper compared to Epson matte black. On many papers, the mearest light touch can easily smudge the Piezography matte black ink. Not such a problem for wall prints, but definitely an issue for zines and books. ...
Interesting comment.? I have usually used STS (source of old MIS) inks.? I bought a sample of Piezo Mk and noticed the dmax was better.? However, more carbon in the solution appears to come with some potential negatives.? On the wall, I don't think anyone notices the differences in dmax.? I suspect Epson decided on its MK carbon ink load based on practical market experience.
FWIW
Paul &
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Using Epson Matte Black instead of Piezography Ultra HD Matte
Hi,
New to the forum. I would normally post this over on the Piezography forum but it's down at the moment and I imagine plenty of you over here will have experience of piezography. Plus I'd thought about dipping my toe in these here waters anyway :)
Has anyone ever tried using official Epson matte black in place of Piezography ultra HD matte black ink? While still using the other Piezography dark, medium and light gray inks, as well as the PIezography Pro linearisation tools.
Roughly speaking, would this work? I envisage some hit to dmax, but that's fine, this is for printing hand made zines and books and so dmax isn't as much a concern as it is for when I make wall prints on fancier papers.
I have a "Piezography Pro" setup on a 3880 and a R3000. I am only using 7 channels on each as I never print gloss/photo black, so my thinking is I would just use one of the two spare channels on each printer for an Epson matte black cartridge. Keeping the Piezography ultra HD matte black cartridge in place for when I make prints.
Why would I do this you ask? Until investing in my piezography setup I had no idea quite how unstable Piezography matte black can be on the surface of the paper compared to Epson matte black. On many papers, the mearest light touch can easily smudge the Piezography matte black ink. Not such a problem for wall prints, but definitely an issue for zines and books. For my first book made using piezography inks () I got around this by using a spray fixative (I found Permajet PermaSeal the best) and really reducing the ink limit as much as possible while still getting a satisfactory dmax. However spraying each page was loooong, not to mention smelly. When printing on the same papers using standard Epson inks the result is vastly more stable to touch.
I do have a P600 still running Epson inks, which I use for colour work, however I predominantly work in BW and I want to keep the Piezography workflow which I have found so precise and efficient for trialling and optimising papers that I may use in my books and zines, not to mention the toning, which I find lifts the end result above what I have ever been able to achieve with Epson inks.
Cheers,
Chris.
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Re: New Epson P5370 Support
Why would I rely on Epson to answer a question regarding QTR?
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Re: New Epson P5370 Support
You should direct your question to Epson.
On Sun, Feb 25, 2024 at 7:24?PM David Pitcher < pitcherd1@...> wrote: Will the latest Epson 17" P5370 be supported or can be treated as a P900? Reading Epson marketing material and other sources the P5370 has the same ink channels and printhead.
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Will the latest Epson 17" P5370 be supported or can be treated as a P900? Reading Epson marketing material and other sources the P5370 has the same ink channels and printhead.
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Re: Just starting out with QTR
Thanks for this Richard. I have also read most of the documentation you have available, and watched your videos, and can appreciate the important advances that your apps provide at the very least to the usability of the system. The process of understanding something in detail often produces moments of uncertainty and confusion. This is the part I like best about learning! I've just been sent a copy of Diallo's description of the system and am finding it answers most of my questions. In the end, I'll probably end up buying your apps in any case. Best....
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Re: Just starting out with QTR
All of these questions are why I initially started writing my huge "How to QTR" book back in 2014. I realized all the ways where the ink descriptor file and curve creation steps could be improved and done much more effeciently. That is what got me started making a few spreadsheet-based tools, and then eventually pushed me learn how to develop real software for my advanced curve creation methods. Yes, you can plod along and read 15 years worth of QTR groups posts where a these questions have been answered dozens of times, and it will?maybe get you where you want to be.?
I'll try to find some old drafts of the curve creation steps, but I don't want to see people waste their time on something that ultimately gives unsatisfactory results (but I completely understand the desire to know exactly how something works and be able do it themselves (which is also why I learned to develop my own software)). But honestly, this traditional method, while it was good when it was the only option, is now totally obsolete. The profiles and tools in my K3 app are miles ahead of even the best ones made with the ink descriptor file.
You can download a trial version or the QTP-Pro and QTP-K3 aps to see how they work, but just wont be able to save the quad curevs (just dismiss the activation screen when it comes up to use in demo mode)?
If you DO want to go through the steps of making the ink separation image at different ink limits, at least use my free Target Generator app so you can create a single ink separation image when setting the limits for each channel indipendently (like K:72, LK: LLK: 64 when calculating the cross over points by hand and so you don't have to print 2-3 separate images with the calibration mode limit slider set differently each time)?
Also, it might be last minute, but if you can get yourself to philadelphia this weekend, I am teaching my 2-day QTR workshop and there is still one spot open.
All the best,?
Richard Boutwell
https://www.richardboutwell.com
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Re: Just starting out with QTR
Thanks again Eben, this is very helpful indeed. I'll keep plodding along....
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Re: Just starting out with QTR
Here’s how I (used to) use it when I was hand-writing profiles. This is based on old, perhaps incorrect, knowledge, so if I’ve got it wrong (a) forgive me, and (b) feel free to set me straight.
DEFAULT_INK_LIMIT=100 - this fills in, for example, the value for LIMIT_C if I neglect to enter a LIMIT_C value. So it’s just a default, to be used if needed. LIMIT_K=50 (or whatever) - the value in your Ink Separation page where K maxes out its density and doesn’t pool. N_OF_GRAY_PARTS=3 (if you have a printer with black, gray, and light gray inks) GRAY_INK_1=K GRAY_INK_2=LK GRAY_INK_3=LLK The GRAY_VAL_XX values are the “crossover” points between the different inks. They are relative to 100%, that is, to full density of the black ink. So I might use? GRAY_VAL_2=45 which means something like the following
I printed a separation page with an overall ink limit of, say, 50, based on my K limit. ?Then I should be using an ink limit for these following steps of 50. Easy way to do that is use DEFAULT_INK_LIMIT=50, of course.?
Given that printout, I found that the LK value reached its maximum at some square - we’ll say the 85% square. I go look at the K chart and find that the density of K at this value - 45 - is the same as my LK was at 85.? It gets one level more indirect when we get to GRAY_VAL_3. It should be the crossover point between LK and LLK, but the value should be expressed in terms of the full K curve. So let’s say the densest LLK is at 70. And suppose further that that is the same density as LK was at 30. The value we want to enter for GRAY_VAL_3 is not 30, but rather is 30% of the crossover point for LK, or 30% * 45, or 13.5 (13 to the nearest integer).
Using other INK_LIMIT’s is a way to scale the ink densities. For instance, if you use the COPY_CURVE keywords (say, for toning curves) you typically add a small percentage of the toning inks by copying the dense, black curves and scaling them down via setting a smaller INK_LIMIT.?
Somewhere there’s probably a really good tutorial on this.?
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On Feb 21, 2024, at 3:07 PM, luigi@... wrote:
Thanks for your reply Eben. Regarding bwmastery, I have read his documentation too. Not sure I want to spend more money, as QTR should be be able to get me where I want to be (maybe not if I don't get any help with this though). I'm trying to understand this process step by step. The documentation I've read is patchy, inconsistent, and often confusing to me. So, baby steps for me...
Step 1: Print ink separation file with PrintTool and no color management on my preferred paper with K3 inks in my P-800
Step 2: Assess patches for the darkest one with no pooling and no noticeable increase in density to the next darkest patch. I used my densitometer for this one and found that 65% for the K step wedge was it.
Is this good so far?
Problems/questions: The documentation appears to assume that the limit will be the same for each of the ink colors, but it's not. Is the 65% value (as established above) what I use for the? DEFAULT_INK_LIMIT variable in the ink descriptor file? Makes sense that "The other limits are effectively scaling factors for how much ink is laid down for each channel." Are these individual ink limits (LIMIT_C, LIMIT_M, etc.) relative to 100% or relative to the value of DEFAULT_INK_LIMIT? I'm not sure the relation between DEFAULT_INK_LIMIT and any individual LIMIT_X, for example.
Luigi
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Re: Just starting out with QTR
Thanks Clay!? I'll have a look....
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Re: Just starting out with QTR
If you are determined to use the ink descriptor file approach, I strongly recommend you download the pdf here:
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Kang-Wei Hsu
Richard Boutwell