QTR-Quadtone RIP

Back to the thread at hand!!! (This is the important part, it’s the QTR forum after all.)

Like I said a few posts back, perceptual linearity is a misnomer so it’s very hard to graph what would appear linear because that makes assumptions about one’s monitor calibration and the dMax of the printed piece. It’s about matching to a monitor. So yes, if the dark curve makes your print match your monitor you are looking at a "perceptually linear" (aka monitor matching) print. If not (if it makes your print darker in the shadows because your monitor/workflow is calibrated differently) than it is no longer a “perceptually linear” print. Because we use a different method of calibrating the on-screen image at IJM, an ICC-printed print with pulled down shadows is now a bit dark and we’ve found reasons why the opposite (non-icc) method works better, mainly for shadow stability. Catch my drift? In this line of work, image data and monitor comes before print and the word “perceptually linear” is really a replacement for “how it looks on my screen". My observations of the underlying math at play between ICC-printed dark dMax and light dMax prints are just observations (all-be-it from 10 years of printing with Create-ICCs) so I can’t really comment on that part. It’s partly obfuscated by how Photoshop utilizes one’s monitor ICC as it is an “ICC aware” application. In the past, the way I (and probably many other people) used Piezography was printing with Create-ICC. This pull-down of the shadows worked well for how I calibrated my screen although sometimes it would make things annoyingly too dark. Pre-Create-ICC I used a combination of Gamma and Dot-Gain in studioprint to match to a gamma 2.2 calibrated 19” LacieCRT. This was (and still is) the closest monitor-to-print match I’ve ever seen but this was a LacieCRT calibrated at 2.2, an image encoded in 1.92, and the printed through a dot-gain of 19. That was a weird-ass route, but it worked.

So in the manual we lay out a method for making one’s screen match a print (that doesn’t utilize icc, just gamma 2.2 images). Included in there is how to do the soft-proofing.

best,
Walker

a note: We spend most of our time at IJM making ink, making ICCs/.quads, shipping ink, selling ink, QC’ing said ink, and taking calls from people who don’t read the manuals that (literally) come with their products. Another 10 percent is spent making new products. The final 10 percent is spent handling the over-load of documentation that has been produced over a 16 year period and also documenting new methods and procedures along with engaging a community of very passionate followers (one of them used to be me).  I was hired to do this but only recently. The person I was replacing was also running the world’s first digital fine-art print-lab (Cone Editions) at the same time as much of the stuff above. So, we are working on it. :) It’s fun. It’s still a lot of work and takes (will take) some time to do it right. Partly why I was so eager to come here and work was to tackle the very problems outlined below in your comment Brian.

upcoming:
Both the Inkjetmall and Piezography website and forum are going to be collected into one place.  (email with details about that coming soon to the IJM mailing list)
Manual is going to be re-written, re-designed, edited, with included best practice information and diy linearization workflow (thanks Roy for the droplet), and updated regularly. It is in need of this, although the information is there. I’ve gotten a ton of useful information from that manual in the past as a printmaker before joining IJM fyi. It’s very useful even as a reference! There are things in there that long-time practitioners can learn!
Piezography OS X install packages will be created with accompanying documentation. These will require QTR to be installed but will enable us to publish updated .quads very frequently in one organized place without bogging down Roy’s distribution schedule.
All old documentation (over 1000 individual urls at this point) will 301-redirect to current documentation (this is the bulk of the work fyi).
And of course more to come (like PiezoDN and Pro), cheers.




> On Apr 19, 2016, at 7:15 AM, brian_downunda@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
> 
> You're kidding me, right?  Clearly you've settled into IJM pretty well, because RTM is the standard IJM response.  I've read and reread the ("new") manual and this stuff is not in there.  That is, not sufficiently clearly and some issues not at all.  People use Piezography despite its documentation, rather than becauseof it.  Although you dismiss the use of an ICC, the preserve numbers workflow is supported in the NPM (p66).  However the overall workflow is particularly poorly described, and it would take a forensic archaeologist to construct a concise and complete one from the NPM.  Nor is it complete - useful information bordering on essential occasionally accidentally dribbles out on the IJM forum, and you have to monitor it like a hawk to catch these gems.  The manual can only really be understood fully by people who don't need it.  I'd like to think that the 2016 NPM update is going to be better, but that's probably just blind optimism, because it's going to be written by the same folks who think that the current version is fine.  Prove me wrong.  
> 
> Coincidentally, I received an unsolicited email via the blog today, and I'll quote some of the contents without naming the author, because it summarises my views and those of others that I speak to: "Unfortunately I find InkjetMall and the Piezography web sites to be a little difficult to digest. Information can be contradictory, incomplete, scattered or just not explained as fully as I would like.  It does not help that it is an evolving process and often posts are written for a previous time, and may not apply today.  I do wish the New manual was clearer, and I suspect I am not alone."  No, that person is most definitely not alone.  Which is precisely why I created the blog.  
> 
> Getting back to the OP Andy's request for "a graph of L* values that would appear linear to a standard observer", my suggestion was to convert the standard 21x4 to an ICC generated by QTR-Create-ICC, print and measure.  I suggested this because it remains my understanding that this was the science behind QTR-Create-ICC.  Is there a better suggestion?
> 
> 
> 
> ---In QuadtoneRIP@yahoogroups.com <mailto:QuadtoneRIP@yahoogroups.com>, <forums@...> wrote :
> 
> I suggest you download and read The New Piezography Manual. It’s the first place to look for Piezography workflow related stuff, and the documentation on this is there. Some things certainly need updating, but that will come in the 2016 edition.
> 
> 
>