Digital BW, The Print

"Yan" <ylucille@...> wrote:
>
> ... new Epson 1400.  ... EB6 inks ...
> 
> Issue #1:  When printing Black Only (using the MIS EEM-BO curve that comes standard with the QTR profiles) I get density shifts that are noticeable in smooth sky sections. ...

I noticed the same thing printing glossy black only.  With my small images on brochures and high contrast images it didn't show up, but for many images I don't think black only is up to the job.
 
 
> Issue #2:  When printing the 100% and 35% calibration chart I noticed that there is not much difference in the density of Light Cyan and Light Magenta. 

LC = 9% Eboni, LM = 6% Eboni.

One way to profile that I like involves using some of the gray inks as "toners" to give more inks firing at the same time.  Just split the ink limit between the gray channel and the toner channel.

> I thus left out Light Cyan when creating my curve since it printed warmer than Light Magenta (LAB B values were consistently higher on EEM paper). 

The peak of warmth is the M 18% ink, though this may depend on the paper.  Usually the K and Y (2%) are the most neutral.  One thing to consider is to make a profile with just the Y and K and then use the sliders to use that and a full inkset profile together, varying the percentages depending on the importance of smoothness v. neutrality. As a target, on Epson Hot Press your paper white to maximum Lab B can be as low as 1.4 units.

> The strange thing is that in my Epson 1400 printer and when printing out the second calibration chart (@ 35%), the max density of my Light Magenta was slightly higher than that of my Light Cyan (L=57.8 for LM vs L=62.7 for LC).

I wonder if that inkset is mixed correctly.  I found an old Eb6 calibration print for Epson Hot Press, and at 35% the LC Lab L = 39, the LM Lab L = 51.


>... seems that my 1400's default density gradient for the LM nozzles is steeper than for the LC. 

My impression has been that all the jets/channels are the same.  That is, when the same ink is fired out at the same level, the resulting density is the same.  For example, a black only profile for K will work if the K ink is put in the C channel and the profile just switched around.

 
> ... averaging out nozzle inconsistencies in my BO prints.  ...


Using more than one channel of K can work.  I used that for the 1800 "3-MK" approach.  Start one channel at a time to get smoother highlights. 

Good luck with the system.

Paul
www.PaulRoark.com