Digital BW, The Print

"Yan" <ylucille@...> wrote:
>
> 
> >  I found an old Eb6 calibration print for Epson Hot Press, and at 35% the LC Lab L = 39, the LM Lab L = 51.

This morning the full Lab reads for Eb6 & Epson HPn, at the 35% patch of the 100% QTR calibration print, are as follows:

LC = 39, 1.3, 2.3 (plus or minus close to 0.2 for the Lab b)

LM = 50.5, 1.8, 3.5  (")


> 
> ...  At 35%, my LC Lab L=63.  Way off! ...

>... the LC ink is the warmest. 

While the above reads make it look like the LM is warmer, where the LM has a Lab L = 39, it's B = 2.1

>  the LC @35% has a LAB B value of 6.7. My LM @35 has a LAB B value of 4.  Huge difference! 

If this is on Epson HPn, I wonder if this is Eboni-based in at all.  

  
> ... I believe that my 4oz LC bottle was filled from an LC reservoir that was not mixed frequently enough to counter the settlement of the carbon particles. ...

When I toured the MIS facility a number of years ago, that was my main criticism of the way they handled inks.  There was no mixing or agitation of the large pigment containers out of which they filled small bottles and, indirectly, I assume, carts.  If MIS is not agitating its Eboni-6 tanks, that could be a problem.

I use Eboni-6 in my 1400, but I don't buy it from MIS.  I have a gallon of the Eboni-6 base that I was able to get from Zeiss a couple of years ago.  So, I mix and QC my own.  That may be a major advantage of Carbon-6 if what we are seeing is MIS QC problems.  I'll notify MIS of the issue.


> wow..all this is starting to remind me of my days as a physics undergrad working with centrifuges and carbon nanotubes...

Did you notice the article recently that carbon nanotubes made the blackest object (print?) yet?  They're still a bit expensive for our uses in B&W, however.

Paul
www.PaulRoark.com