PiezoDN Limiting the ink load

InkjetMall Customer Support Piezography Inks & Printing
1

Hello Walker,

I would like to limit the inkload for printing a negative for a customer. It is for a silver gelatin darkroom workflow.

The first negative was printed using the MasterPiezoDN.quad ( PiezoPro inks on a Epson 9800, Pictorico Ultra OHP )

The sivergelatin print has no detail in the highlights, the rows 255 and 239 are completely white, the Luminocity values measure around 96….( colorport i1Pro)

I marked the first patch red where the Luminocity-numbers start to lower.

We did determine minimum exposure time to achieve black at 9 seconds, the limiter file was made with the same exposure time.

(For this mail I flipped the limiter target horizontaly)

inkjetmallgrab

[img]

What would now be my limit number? And what would then be the first in- and output values in the Piezography curve adjustment tool?

The example in your Piezo DN Manual reads input 251 > output 216

Schermafbeelding 2022-01-24 om 13.20.32

Kind Regards,

Luc Brefeld

2

Dear Luc,

Patch 217 is the first TONE patch so you would limit this to 218 (limit to first specular white patch) in PPEv2.

Right here:
Screen Shot 2022-01-24 at 11.16.08 AM

Ideally we would also like to keep the black (spectral highlight 255 at full ink load. So In this case you would do the following.

  1. Open PPEv2 and delete measurements (you don’t need those).
  2. Go to your starting curve and copy/paste the starting curve in there.
  3. Go to Highlight Start Point and set to 218
  4. Go to New Curve and copy/paste into a new txt doc in Sublime Txt.
  5. Go to the first number after each of the curve channel headers in your old curve (aka the number just below # C Curve, #M Curve, etc) and copy/paste over the top number in the new curve. This will fully re “mask” the highlight with full density.
  6. Your new curve is now limited AND has all density in the highlights for good spectral white.

best regards
-Walker