D(max) caculated based on Lab


Target (129 patches) printed on Hahnemühle Photo Rag 308 with P2 NU set and SC P 600.
Measuring with X-Rite ColorMunki Photo and ColorPicker.

How to calculate D (and Dmax) with the measuring results (Lab)?



I’ve had the same question and my understanding is that they are not the same type of measurement, density vs reflectance, and there is not a straight conversion. I found this blog post that shared these numbers:

dMax L
1.81 12.92
1.77 13.70
1.70 15.45
1.65 16.70

Given this, the advertised dMax of HD Matte Black ink on Hahnemuhle Photo Rag paper would be an L value of 12.92.

The darkest I’ve measured with my P800 on Type2 paper is an L value of 16.3. This certainly isn’t as dark as some people claim to be measuring but it is much darker than the previous matte black ink and is very pleasing to my eyes.

16.3 is pretty high dMax IMO, T2 is closer to 15.6 on the P800 . . . so maybe you don’t have all the epson ink out yet? I suggest printing a calibration target (in QTR calibration mode, not 16bit) and measuring the actual 100% UHD ink density:

VPI-10InkSep.tif.zip (674.1 KB)

UHD actually goes to 12.43 L* on the 3800 and HPR308.


Walker, OK I’ll print and measuring (L*,a,b,) the calibration target.
For your info, the printer was new and from the beginning equipped with the P2-set.

Dear Walker,

Results …

SC P-600
ColorMunki - spot measurements - ColorPicker
Target: VPI-10InkSep

Cartridge position as following in SC-P-600

check of channels

printed target

channels / shades (number 1 - 9 is position from left to right in SC P-600)


results of L* measurements

chart of the L* measurements per channel / shade

Anny thoughts or advice:

  • espacially for the results of HD Photo Black.
  • and lowest L* on UHD is 14.68 versus +/- 12 what could be reached



aside from the PK having some variability due to sensor placement, looks about right. UHD is a little light but it’s a 2 picoliter printer so that stands to reason it would be lighter than the 3.5 pL of the P800s . . . but did you dry over night?

Please mail me the target, I’d like to measure on our devices here too. It could be the device.



I’ve remeasured the same print of the Target, with the following ‘better’ results for the UHD Matt Black and same results for the other Shades.

Thanks for the advice concerning the ‘sensor’ placement. It helped to get ‘better’ measurements.

I’ll mail the printed Target.



Peter. I tried looking up your records and I have no record of sale or delivery of UHD ink. I’m trying to find the lot# for your ink bottle. Please private message me the order # if you could. Did you get this from someone else?