Gravure Curve

PiezoDN Digital Negatives
1

Hey everyone. Here is the initial Beta Curve for Gravure. It is just off the top of my head.

It should give roughly a 1.4 dMax as the maximum dMax.

It uses a normal PiezoDN channel configuration (for Selenium ink set).

best,
Walker

Gravure-Test-V1.quad_-1.zip (4.02 KB)

2

One person coming on here needs Magenta mapped to Yellow.

Here it is.

[attachment file=29613]

Gravure-Test-V1-M-to-Y.quad_-1.zip (4.07 KB)

3

And here is M to LLK for the other customer who needed that mapping.

Gravure-Test-V1-M-to-LLK.quad_.zip (3.53 KB)

4

What application folder should the gravure.quad go into?

5

put it in the (your-printer-model)-PiezoDN folder.

best,
Walker

6

Just a note on this. The limiting of the density was done with some old data and during a teaching session in a few mins when I had free time so it most likely will be more dense than it needs to be. If so, the normal PiezoDN limiting workflow as documented in the manual will work to get the correct density for patch 128 (of 129) “aka the nearest white to paper white”.

If someone here posts the required “best” UV densities (any number, 21, 31, etc) from OHP base to max-density, I can make and publish a better Gravure master curve on Monday as I have a tool that can do target density to final density calibration (instead of measuring from printed paper patches like normal PiezoDN process).

best,
Walker

7

I noticed some K ink values in the wrong place on the first .quad (the remapped ones are fine).

There should be no shade 1 printing at all.

Here is the updated curve (same densities, not guaranteed to work until over-all densities are moved into place but it’s a start).

Gravure-Test-V1b.quad_.zip (4.13 KB)

8

I have tried copying the Gravure-test V1b.quad to the applications>piezography>curves>9890 folder, and to the library>printers folders to no avail. Print Tools does not see it for some reason. Can anyone offer advice as to where I’m missing the mark?

Thanks,

Jim

9

Starting with the simplest possibilities:

  1. Close and reopen PrintTool to refresh the list.
  2. Look for an error clue in the Terminal window after running the Install.command?
Walker will probably have some other ideas.
10

Thanks, Keith,

I just dragged the file to the folder. Did not run an install as the file was posted by itself. I’m guessing this is the issue.

I did close Print Tools and reopen - to no avail.

11

Yes - whenever you have a new quad to install, whether one you have made yourself or one from another source as with this one, you have to put it in the PiezoDN folder for your printer and run the install.command

This is standard procedure for installing all QTR curves.

 

12

I assumed that you had read the instruction on how to install a .quad.

So after dragging to the curve folder, run the Install(printermodel).command that is in that folder. It will update the available curve list in the quadtonerip driver.

best,
Walker

13

Hi Walker,

I would like to start printing positive films for photoetching (using PurEtch - photopolymer film - on copper plate). My set up: Pro inks on a 9900. This Gravure Beta curve seems to be for K7 - would it be useful for me? Or do you have any other suggestions that might help me out?

Thanks!

14

I can upload a beta Pro ink curve in a bit.

 

best,

Walker

1 Like
15

Awesome, thanks Walker!

Best,
Camille

16

Dear Camille. I see that you are a beta tester.

With the Piezography Professional beta tool (>Applications>Piezography>Driver>Tools>) you can do this even better yourself.

  1. Load a normal positive curve into the PP tool (I would do the Neutral Baryta Photo curve).

  2. Print 256 steps with the same curve on your film.

  3. Measure the OPTICAL or UV-OPTICAL DENSITY of these steps with a densitometer and place the 256 density measurements in the measurements tab.

  4. Look at the measurements and identify you maximum density step (dMax of 1.4ish).

  5. Count from the top (255) down until you find your density (example: step 240).

  6. Set your Highlight Start Point to the step that had your desired maximum density (eg: 240)

  7. The “New Curve” will have linear density and also be limited to your maximum density 1.4

  8. Print a second step piece of film (256 steps) with the new curve and make a gravure plate with this new film + aquatint etc in the normal way you do.

  9. Measure the reflected densities off of the third or fourth press of this new step plate.

  10. Linearize the curve you used to print the plate steps using these measured reflected densities from the paper-printed image.

This process should get you the best darn copper gravure system out-there.

 

best,

Walker

 

17

Hi Walker,

Thanks for the instructions. I printed the 256 steps target using the Canson-BarytaPhoto-N curve, and let it dry for a day.

We don’t have a densitometer here, but if I understand correctly, I can use my i1Pro and export density measurements with ColorPort - am I right?

My question is: do I need to place a sheet of paper (ex. a piece of polypropylene) behind my Pictorico (on which I printed my target)? Will that influence the readings? Or should I just measure the Pictorico placed on the i1’s backup board?

Thank you!

18

The film positive is not measured with PiezoDN. You measure the gravure print. You are to take the film and make a plate with it and produce a gravure print. Then the measurements made with your Eye1 of the gravure print are used in our software to alter the curve which produced that film to make a new curve to produce a new film positive.