Digital BW, The Print

I searched around on the forum, but wasn't sure if what I am experiencing is what is referred to as "artifacts" in other posts. I'm using an Epson r280 with UT-RC (glossy black)inks and Kirkland paper. I noticed recently that deep blacks(maybe "pure" blacks) look odd when the print is viewed at an angle.  Kind of a reflection or like something is on top of the paper.
Prior to this setup I used an Epson R220 with UT-R2(glossy) and the same paper, but never had this problem. Is this a known issue(if so, any recommendations?) or more likely an issue with my printer?

Thanks in advance,

Gabe

From you description it sounds like you are describing what is often referred to as "bronzing" or "gloss differential".  It is a function of the paper and the ink set.  Sorry I don't have any specific recommendations for you, but perhaps the above search terms will help you find some more info.  I'm sure some one more knowledgeable than me will swing by with more input.

Ken

Ken,

Thanks for the reply. I did the search you suggested, and a series of posts on "solarization" seemed to be a similar case to mine. Photo Black seems to be the culprit. I was just surprised in the difference between the UT-R2 and RC inks in terms of "bronzing" The solution in the "solarization" case seemed to be either spray or a different paper.

"acevbolt" <acevbolt@...> wrote:
>
> ... I'm using an Epson r280 with UT-RC (glossy black)inks and Kirkland paper. I noticed recently that deep blacks(maybe "pure" blacks) look odd when the print is viewed at an angle.  Kind of a reflection or like something is on top of the paper.

It sounds like they could be overloaded.  I'm curious if when you print a 90-100% test strip -- like this one: http://www.paulroark.com/BW-Info/90-100.jpg -- if the dmax is reached at other than the 100% patch.  It may be hard to tell without a spectro or flatbed scanner.  If you have a flatbed, use black paper around the test strip to reduce flare.

Looking at my curves for the 260 and 1400, it appears that they were not topping out too soon.


> Prior to this setup I used an Epson R220 with UT-R2(glossy) and the same paper, but never had this problem. ...

The 220 is a different printer with different characteristics.  In fact, for that one I came up with a special PK to optimize it.

In general, I do sometimes see a 100% black that is just too shiny relative to the 95% patch.  Using gloss optimizer or a spray can take care of it, but that is a nuisance.  See on the 90-100 test strip one of the patches below 100% looks better and still has a sufficient depth of black.  If so, it's easy to make a curve that will take care of the problem.

Paul
www.PaulRoark.com

Hi Paul,

Thanks for the suggestions

>I'm curious if when you print a 90-100% test strip --  If you have a flatbed, use black paper around the test strip to reduce flare.
> 

Visually, there was sharp jump from the 99% patch to the 100% patch when viewed at an angle(the 100% looking really really black and shiny)

I did a quick flatbed scan(can't access my gray card at this very moment), and sampled the L-values in each patch(5pixel average dropper).
From 90-100% I got the following numbers:

24,21,20,18,16,16,14,14,10,10,14 


> 
> In general, I do sometimes see a 100% black that is just too shiny relative to the 95% patch.  Using gloss optimizer or a spray can take care of it, but that is a nuisance.  See on the 90-100 test strip one of the patches below 100% looks better and still has a sufficient depth of black.  If so, it's easy to make a curve that will take care of the problem.
> 

From here I'm not sure how to make the curve. I do have access to a gray card for future work.


Thanks, 

Gabe

Hi Gabe,

 
> >... print a 90-100% test strip ...


> Visually, there was sharp jump from the 99% patch to the 100% patch when viewed at an angle(the 100% looking really really black and shiny)
> 
> ...the L-values ... From 90-100%:
> 
> 24,21,20,18,16,16,14,14,10,10,14 

So, it does look like overloading may be the problem.

> From here I'm not sure how to make the curve. 

What is your current workflow?  Epson driver, with or without an ICC, or QTR (which profile)?

Paul
www.PaulRoark.com

Hi Paul
 
> What is your current workflow?  Epson driver, with or without an ICC, or QTR (which profile)?

Images are saved as grayscale(either 8 or 16bit).
I print with the QTR-260-Kirkland Glossy ICC profile that came in the zipfile, using the printer settings suggested in your PDF for the r260. The only change i've made is setting the Gamma in the Epson driver to 1.8 since at 2.2 it was coming out too dark(with profiled monitor). I'm also using a combination of neutral light inks and warm for the rest that you suggested earlier this year.

thanks again,

Gabe

On 12/29/2009 1:16 AM, acevbolt wrote:
>
> I searched around on the forum, but wasn't sure if what I am 
> experiencing is what is referred to as "artifacts" in other posts. I'm 
> using an Epson r280 with UT-RC (glossy black)inks and Kirkland paper. 
> I noticed recently that deep blacks(maybe "pure" blacks) look odd when 
> the print is viewed at an angle. Kind of a reflection or like 
> something is on top of the paper.
> Prior to this setup I used an Epson R220 with UT-R2(glossy) and the 
> same paper, but never had this problem. Is this a known issue(if so, 
> any recommendations?) or more likely an issue with my printer?
>
> Thanks in advance,
>
> Gabe
>
> 
I believe what you see is "metamrism" (sp?).  Some dye based ink jet 
inks cause this problem.



[Non-text portions of this message have been removed]

Theresa

I may of course be wrong, however metamerism, at least in the context of
inkjet prints, is where the colours of the print change under different
light sources.  All dyes and pigments are metameric to some extent, however
some of the early inkjet dyes and pigments exhibited significant metamerism.
The latest inksets have now got this pretty much under control so that for
most people and purposes it is no longer a problem.

The issue Gabe seems to be suffering from seems to be "bronzing".  This can
be caused by the differing reflectivities of the inks compared to the paper
surface itself (or indeed to other inks) or sometimes by a surplus of ink
which is not being taken up by the paper.  From his postings it looks as
though it is the latter problem which can be cured with a good/better
profile.  A good profile can also go a long way to curing bronzing caused by
different reflectivities as well.

David Whistance

  -----Original Message-----
  From: DigitalBlackandWhiteThePrint@yahoogroups.com
[mailto:DigitalBlackandWhiteThePrint@yahoogroups.com]On Behalf Of Theresa
  Sent: 31 December 2009 12:14
  To: DigitalBlackandWhiteThePrint@yahoogroups.com
  Subject: Re: [Digital BW] Deep blacks seem reflective when viewed from
side (UT-RC and Epson R280)



  On 12/29/2009 1:16 AM, acevbolt wrote:
  >
  > I searched around on the forum, but wasn't sure if what I am
  > experiencing is what is referred to as "artifacts" in other posts. I'm
  > using an Epson r280 with UT-RC (glossy black)inks and Kirkland paper.
  > I noticed recently that deep blacks(maybe "pure" blacks) look odd when
  > the print is viewed at an angle. Kind of a reflection or like
  > something is on top of the paper.
  > Prior to this setup I used an Epson R220 with UT-R2(glossy) and the
  > same paper, but never had this problem. Is this a known issue(if so,
  > any recommendations?) or more likely an issue with my printer?
  >
  > Thanks in advance,
  >
  > Gabe
  >
  >
  I believe what you see is "metamrism" (sp?). Some dye based ink jet
  inks cause this problem.

  [Non-text portions of this message have been removed]



  


[Non-text portions of this message have been removed]