Relinearizing curves: several just fine, but some disasters - all black

Using Tool 2.2.1
OK… I’m lost.

Over the years, I’ve made and linearized dozens of Piezo quad curves, although I’ve not relinearized in the past 3 years or so…

I have 5 go to papers: Epson Cold/Hot press natural; Hahnemuhle Proto Rag; Arches Velim Museum Rag; Epson Velvet Fine art and (for sanity testing) Red River Aurora Art Natural.

I created the curves for these years ago, and the linearlized them all twice (which I called version 1, version 2 and version 3), to get things as straight as I could. The last time I did that was about 3 years ago, so a few days ago, I thought I’d give them all another pass.

I printed the Piezography-256step-i1Pro2.tif using the last (version 3) iteration of my linearized curves on the appropriate paper. Printed on all 5 papers, and then let them dry for 36 hours.

The resulting targets all look very nice and even, as I’d expect. No glaring errors standing out; nice even gradations.

So I scanned them, and did this:

  1. saved the measurement data as LAB data in cgats format. Open this in text editor and copy the lab data

  2. go to the MEASUREMENTS sheet. Clear all in the first column, & Paste the measurement data.

  3. Open the curve/.quad file used to print the target, select all and copy.

  4. In excel, go to STARTING CURVE and clear contents of A column. Click A1 and paste

  5. go to home sheet and set both smoothing to Zero. 0

  6. Choose smooth amount and boost to make the red line slightly wavy. NOT TOO MUCH!

  7. Go to NEW CURVE and copy all the data

  8. paste into the new .quad file and save

  9. remember to set prefs to 666 and then install.

Near as I can tell, these are the correct steps.

Here’s what has stumped me: Two of the new linearized curves are just fine; three are totally useless.

Velvet Fine Art, and Aurora Art natural both linearized without issues, BUT the Epson CPN, the Hahn Photo Rag and the AVMR papers all print my test image nearly pitch black (not exaggerating), and virtually identical to each other.

So, I rescanned - no change. I switched computers to do the scanning - no change. Rebooted - no change. Verified that my Version 3 source curves print fine.

Again, the targets printed from Piezography-256step-i1Pro2.tif look to be virtually identical (although I can see that column N is a bit darker on the Epson paper than on the others, but it is still lighter than column O.)

Two are fine; three are nearly pitch black.

Fortunately, I have working version 3’s of two of the three bad ones, but the Hahnemuhle was created against my VFA version 3, so I don’t really have a linearized curve for the Hahn PHoto Rag yet.

I’m not dead in the water here, but I’d going on 10 hours messing with this today, and I’ll admit to being mightily frustrated by this!

Advice, laughter and/or pity all greatly appreciated.

(Yeah, yeah: if it ain’t broke…) My bad.

EDIT: Epson 3880 with channel swapped M to LLK. Swap has been in place since day one, and all curves were made with it.

this is a permissions issue if they are pitch black.

Set permissions to read-write for everyone on the .quads. Re-install and it should be ok


1 Like

I’ll be darned. I repeatedly checked to ensure that all the permissions were set before installing. (In fact, they would not install at all if I didn’t have it correct.) But sure enough, once installed, the permissions were incorrect. Not sure I’ve ever seen that. What finally worked was for me to First delete all the installed quads from the system library/printers… and then run the installer again.
That did the trick. Very odd, but thanks!
(Hope you are feeling better… :slight_smile:

1 Like