Curves for different K7 ink sets/papers


#1

I am probably about to order a selenium K7 for my R2000. But first, a couple of newbie questions. Forgive me if they seem too newbie…, but I did not see any reference in The New Piezography Manual.

I see, in QTRip, where to select the printer, then the R2000 K7. That part is fine. Then I go to the curves and select a curve for the paper I’m using. I find it interesting that the curves are for papers only, not papers matched with ink sets. Does this mean that, when IJM develops an inkset, that they design it to work with the existing K7 paper profile for a given paper? For example, if I want to print on Hahnemuhle Photo Rag using Sel K7, I just select R2000, R2000 K7, then K7-2880-HanPhotoRag? Then, if I have a K7 Carbon, and I want to print on the same paper, I use the same curve?

If so, this strikes me as incredible that IJM was able to design their B&W ink sets so that they all can use the same curve for a given paper. I’d have thought that they’d need to be linearized, at the very least.

Larry


#2

Older K7 curves were all built for ALL insets (using a single curve). new K7 curves are built for individual inksets and a slightly more specific to each inkset. They all should work just fine but test and try.

New curves can often be found at Piezography.com

We’ll have a package for downloading that will include the entire archive soon.

best,
Walker


#3

The newest curves I can find on piezography.com are from 2014 (http://www.piezography.com/PiezoPress/blog/piezography-k7-inks-and-curves/new-glossy-curves-library/) and are not the ones specific for insets. I don’t recall coming across quad files specific for inksets. Can you dig up the link for me please (unless the downloading package you’re preparing will be ready in a matter of weeks… I am planning to order my Sel K7 set very soon now).

Larry


#4

LarryB. I’m PMing you.

W


#5

Thanks!

L


#6

Figures, just my luck. Once I finally get around to ordering, Forum15 coupon code is removed.

Is another promotion coming up soon?

Larry


#7

try FORUM15


#8

Ah, thanks Jon.

I forgot, when it doubt, shout at the computer!

Larry


#9

I thought FORUM15 applied to all complete sets of inks or cartridges. It worked on the Selenium ink, but no other sets.
Larry


#10

[QUOTE=LarryB;11155][QUOTE=walkerblackwell;11154]Older K7 curves were all built for ALL insets (using a single curve). new K7 curves are built for individual inksets and a slightly more specific to each inkset. They all should work just fine but test and try.[/QUOTE]
The newest curves I can find on piezography.com are from 2014 (http://www.piezography.com/PiezoPress/blog/piezography-k7-inks-and-curves/new-glossy-curves-library/) and are not the ones specific for insets. I don’t recall coming across quad files specific for inksets. Can you dig up the link for me please (unless the downloading package you’re preparing will be ready in a matter of weeks… I am planning to order my Sel K7 set very soon now).[/QUOTE]

I’m a bit late to this, but perhaps I can add an historical perspective. A long time ago, i.e. before this forum, the message from IJM was that shade 1 in one inkset was interchangeable with shade 1 of another inkset, and the same for shade 2 and so on. The inks were formulated this way by design. In fact, I recall one user on the old Yahoo Piezography forum who was mixing his own inkset from the five standard ones and was told by Jon that the shades were interchangeable, which made mixing inksets straightforward so long as you didn’t mix the shades - i.e. you still used the same QTR curves.

Hence there weren’t any inkset-specific K7 curves, because supposedly there wasn’t any need. You used one curve for all five inksets.

A year of two ago ago it started dribbling out on this forum that in fact the shades weren’t exactly interchangeable - close but not quite. It’s never been clear to me whether this was always the case, or whether the inks had been reformulated, as apparently occasionally happens but is rarely announced. Whatever, this little piece of information was like another fragment of the Dead Sea Scrolls emerging from the desert sands.

So the P2 curves are inkset-specific. Jon has said that P2 needs this whereas K7 doesn’t, but I suspect that if the K7 curves were all being produced from scratch now, they would probably be inkset-specific too. My hunch is that the shades where never quite as interchangeable as was once claimed.

So this is why you can find inkset-specific P2 curves but only generic K7 curves.


#11

Frankly, we just want to be more exact in our profiling and the level that people are at now with knowing how to print Piezography allows us to do hue specific profiling without tripping people up (fingers crossed). However, a few have already been tripped up by the P2s because they are hue specific and then they think they can’t use one hue profile for their inkset of another hue. They [I]can[/I] but having hue specific raises the bar. See? It’s a psychological thing. We have hundred and hundreds (more than 500) curves. If we did hue-specific that would be multiplied by 5. We are doing this for new printers and long-term pro-printers only.

The most important thing is to get tools into peoples hand’s to let them lin their own curves at the moment (or do it for other [I]Piezography[/I] customers) and that is what we’re working on + creating the curve (etc) Piezography package that has it all in one place.

best,
Walker


#12

There’s an aspect to this that needs to be spelt out clearly. On the Yahoo QTR forum recently, I remarked to you that people use Piezography [I]despite[/I] its documentation, rather than because of it. We know that you’re putting in a huge effort to ensure that it’s all organised and easy to find, and that will be a good thing. But organisation is only part of it - there’s also completeness. IHMO there are gaps. When people ask questions, they’re often told to read the NPM, but frankly there’s no chance of that document winning any literary prizes. And moreover it doesn’t fill many of the gaps, or if it does so then only very cryptically.

As Bob rhj1007 observed in this post, useful information sometimes dribbles out almost by accident in forum posts. JeffG and I have made the same observation a number of times. There are a number of occasions over the years when in response to a forum post I’ve exclaimed “oh, my goodness gracious me!” (or words to that effect), “I didn’t know that and really wish I had read that earlier”.

Whether or not the same shades in different inksets are interchangeable, and thus whether generic curves or inkset-specific curves are needed, is a classic case. We were definitely told years ago that they were interchangeable and now we’re told that they’re not quite. This is not an academic point only applicable to those creating custom mixes, it also applies to anyone using more than one inkset. Even with your forthcoming linearisation tools, such people need to know whether to do this once per paper or for each inkset.

If you don’t want confused or frustrated users, then IJM needs to be more upfront about the finer points of Piezography, including when your views on something change. Frankly.


#13

The digital world changes. So do papers. It’s complex and requires flexible and adaptable thought to grasp the totality of the project at hand.

Epson doesn’t have to deal with this difference in papers related to carbon chemistry because they space their dots so wide and plus they pretend that no other papers exist besides those they private label (take “Legacy” paper for example. they have a business interest in never making media types for non-sold printers). We deal with a wide-gamut of papers, skill-levels, expectations, printer-model, etc. Why is it an issue that we start to slowly publish hue-specific P2 curves (or K7 with newer printers)? 80 percent of our customers would still be making prints better than anything else they saw if we published one curve per paper. But Piezography is a [I]premium product [/I]and we are going to deliver the best for whatever paper emulsion exists in the world end of story. If we can do better than a single curve for all hue-sets (even if that is the best currently) because that paper chemistry requires 5 different curves, we are going to do that.

Last month we revolutionized the darkroom. You will hear about this in about a year (outside of this forum). Basically we figured out how to fully profile it. I’m sure a million people will be pissed at us because we came out with something other than the shade 2.5 and 4.5 method that came before. But you know what? This medium is young and growing and vital and strong. We are representative of that.

Our pigment is unique and sells itself. We live up to its quality. We continue to make the best profiles for it (regardless of if that profile is hue-specific or not) and the papers it prints on but going forward we (I) [I]hope[/I] to build more specific curves for individual hue-sets. These do not diminish the quality of the curves that came before. They only maximize the quality of the new curves for the new generation of papers and batches that exist [I]today.[/I]We stand by our work, use it at Cone Editions daily for and with artists, and know its inherent value. We make it better every day. We follow the path of Kaizen and for anyone who has not been introduced to that concept I suggest you look it up.

This forum is a give and take. It is a combination of evolutionary talk, discussion, complaints, and progress: on the public record. In the end it will result in something fantastic and certainly not a scroll in a sea.

best,
Walker


#14

I think many piezography users are always living on the cusp of “new technology” which requires frequent changes in documentation. As a scientist I can respect that. I think that IJM could use two manuals for piezography. One “Basic Piezography” that would describe the basic workflow for K7, P2, and DN. I would keep the “Basic Manual” at 1 curve for each paper and say they’re adequate for all ink sets. It’s unclear to me whether P2 can get away with one curve for each ink set as well. I suspect that basic beginner results could be achieved this way, but I may be wrong. DN sounds kind of advanced, so maybe that shouldn’t even be in a “Basic Manual”. The “Basic Manual” should clearly direct the user to curves. I would hope this link would be located on the webpage that sells the ink. Note that IJM provides easy access to profiles for their colour inks, although it used to be easier to see the link. It does exist though. I would hope that a link to downloadable proofing profiles would exist side by side the curves for QTR.

I’m not trying to tell anyone how to do his job here, although I suppose it may sound like it (sorry if it does!). I can see the gaps that Brian is referring to, but I think some of the gaps are related to more advanced topics. At a basic level, one profile is good for all ink sets for a particular paper. This probably wasn’t explained in the original NPM because, at the time, P2 wasn’t described in the manual, so there was no such confusion. Now we have P2 with separate profiles for each ink set which has created a knowledge gap.

Walker has a huge mountain of work to do there. It’s kind of too bad that piezography technology developed with little attention to documentation for quite a few years. I’m sure it has been exciting to be developing all the new ink sets, curves, methods, and so on. For those who have been using Piezography for years and kept up with the changes, it’s been no big deal. For some one like me that has come into the art form at this time, I am really appreciating the help I’ve been getting on this forum from Walker, Brian, and others. Perhaps Brian should be compensated for his help here on this forum. Make sure you pay him in US dollars! I already paid him more than just an arm or a leg, I gave him a head! (OK, a dead, defunct, printer head, but a head nonetheless.)

Keep up the great work Walker!
Larry


#15

[QUOTE=walkerblackwell;11229]The digital world changes. So do papers. It’s complex and requires flexible and adaptable thought to grasp the totality of the project at hand.[/QUOTE]

This just underlines the point I was making.