QTR-Quadtone RIP

I’ve been working on getting more number data (rows) into the linearizer (129 at the moment) to get it to really sing. It requires some interesting number stuff to say the least . . . I’ll post on this if I can get it good.

Re Piezo curves vs other curves, really it’s all in the eye of the beholder. I’ve been a professional printmaker for well over a decade and have progressed from dual quad on a 9000 using (ImagePrint can you believe it?) all the way to really crazy K7 and K8 and K9 (alpha channel) setups that I built at Black Point Editions using StudioPrint (and not much underprinting compared to current Piezo curves.) I really liked how studioprint (working on a curve layout built by Jon) lacked much under-print. This enabled myself and Tyler and a few of the other professional labs out there to really get distinct hue-splits on certain inksets while maintaining either dual-quad or K7 setups. But with low underprinting, you get extremely damaged prints with a single nozzle drop half-way through the print. You see it! Also you have to relin every time you do a big print-job or when simple environmental or paper-batches change.

That said, I’ve done a ton descriptor file work for K3, and K4 inks with color toning. I was never happy with the matte printing but did a bunch of semi-gloss papers with custom .quads for the 11880 and was very happy with them. My descriptors were so different from what the norm in this community is that I never really published them . . . I guess I didn’t have much time to document and didn’t want the questions when I was busy just printing for people. I can get back in there if anyone here wants 11880 quads . . . The 9900s work pretty well with the 11880 too . . .

Every curve does something unique. Now that I’m in the belly of it I can describe a bit of how piezography curves are built. What we do with Piezography QTR curves is take all the variables that effect a print, paper variables, environmental variables, ink chemistry, ink hue and physical characteristics, head and nozzle characteristics and physics, and we build something that can work on a bunch of different copies of the same printer model for a long time and print smooth with minimal noise and maximum frequency/nozzles. We calibrate that curve in such a way that it’s mathematically smooth, meaning when another person goes and does a linearization on their own system it will work and they can physically print 256 separations of gray regardless of their linearity.* There’s a note there: someone linearizing a piezo quad has to first put good unexpired non-sedimented inks in there and have them in the right place and have whatever other ink they may have had in, flushed out properly. The other thing we do in Piezo-land is enforce a gray gamma 2.2 workflow from monitor though print . . . but there is no reason why someone can’t calibrate a piezo .quad for some other gamma regime . . .

cheers and happy Thursday,
Walker



> On Apr 7, 2016, at 6:34 PM, brian_downunda@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
> 
> The short version is that you can't create your own Piezography curve for an paper that doesn't have one - only IJM can do that.  The best that you can do is take an existing Piezography curve for a similar paper and using your i1 and Roy's relinearisation droplet, relinearise that curve for the new paper.  Details on how to do this with current technology:  http://www.cyberhalides.com/piezography-printing/re-linearising-a-piezo-curve/ <http://www.cyberhalides.com/piezography-printing/re-linearising-a-piezo-curve/>
>  
> Walker is developing a new and improved way of using the relinearisation droplet, but the existing approach is working pretty darn well for those of use who have been using it since it was released by Roy last year.
> 
> Or you could create your own QTR curve from scratch, using the standard QTR documentation, or the service that Richard is offering.  However strictly speaking this won't be a Piezography curve.  How much better or worse or simply different would this be to a custom or relinearised Piezography curve?  I suspect that everyone one here will have a different answer to this question.  IJM will claim that Piezography is a system, and their particular style of curves are part of that system and part of the style of print that it generates.
> 
>