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Author Topic: QuadToneRIP QTR - Unexpected Color Tint  (Read 3121 times)

Jasper

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Re: QuadToneRIP QTR - Unexpected Color Tint
« Reply #20 on: March 22, 2018, 08:04:29 PM »

The added complication, if you're after exact neutral, is the impact of the paper base color.  You may need to tweak for each paper.  Which is one of the complications of Piezography K7 inks.  Many people don't find their neutral inkset as neutral as they claim, even on Hahnemuhle Photo Rag, but with K7 you can't tweak, other than to change to a different paper. 

The Inkjetmall solution to this is their new Pro inkset, which has both warm and cool tonings that you combine to achieve various effects.  So you could achieve an exact neutral, although it may again be trial and error for each paper.  And you lose part of the attraction of Piezography, as you are reduced from seven to four shades on most printers.  But at least you can tweak

I think exact neutral is over-rated and boring.  Find a subtle toning that you like.

Hi Ferp - I agree with your general sentiment.  Although I wouldn't necessarily call neutral prints "over-rated" or "boring", I do prefer a subtle tone and I will very likely go for that when I switch to piezo (probably selenium).
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datro

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Re: QuadToneRIP QTR - Unexpected Color Tint
« Reply #21 on: March 23, 2018, 08:27:57 AM »

I agree with others that the three Epson black inks are not neutral.  I'd have said warm rather than green, but it may depend on which generation Epson inkset you're using.  You can see this by examining the "warm" curves that ship with QTR which use only the thee black inks without any colors added for toning effect.

Both ABW and QTR have to add in small amounts of the color inks to achieve a neutral print.  Unlike Mr Rodney, in my experience neither of them is particularly successful.  I find ABW prints at the neutral setting to be a bit cooler than neutral, and for this reason I can usually spot a "neutral" ABW print in an exhibition.  QTR neutral is a bit warmer than neutral.

You can tweak both approaches to achieve a more neutral print.  It's easier to do this in ABW because there is a color toning wheel in advanced color settings, but it's still trial and error process as the on-screen simulation isn't particularly accurate. Adjusting the toning of an ABW curve is an advanced process and most users would be better advised just to combine two curves.

The added complication, if you're after exact neutral, is the impact of the paper base color.  You may need to tweak for each paper.  Which is one of the complications of Piezography K7 inks.  Many people don't find their neutral inkset as neutral as they claim, even on Hahnemuhle Photo Rag, but with K7 you can't tweak, other than to change to a different paper. 

The Inkjetmall solution to this is their new Pro inkset, which has both warm and cool tonings that you combine to achieve various effects.  So you could achieve an exact neutral, although it may again be trial and error for each paper.  And you lose part of the attraction of Piezography, as you are reduced from seven to four shades on most printers.  But at least you can tweak

I think exact neutral is over-rated and boring.  Find a subtle toning that you like.
+1
Epson K inks are most definitely NOT neutral.

Sent from my TouchPad using Tapatalk

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unesco

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Re: QuadToneRIP QTR - Unexpected Color Tint
« Reply #22 on: March 23, 2018, 01:48:54 PM »

Just tried printing my first B+W image using QTR and there is a clear green tint  :(

(...)

Any ideas why there is a tint to the image?  Are Epson's K, LK, LLK Inks neutral or not?

Epson K, LK, LLK inks are not neutral, they are close to mustard/olive tint what is usual to carbon based inks.
There are two approaches for black inks: Canon and HP having near neutral blacks - these are carbon based inks with addition of some cold tint dyes in the liquid. Epson approach is different, inks are warm and neutralisation is done by adding C/M tint directly on paper.

You can receive very neutral prints from QTR, however it is not easy, and one of the highest advantages of QTR is ability of duo/tri toning by curve blending.
ABW is far from neutral, but of course closer than anyone's first attempt to QTR. Many things depend on the paper tint you use, since there is no clear "neutral" definition once you change papers.
Good luck with QTR, it is worth trying if you have a lot of patience! Results can be outstanding.
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Ferp

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Re: QuadToneRIP QTR - Unexpected Color Tint
« Reply #23 on: March 24, 2018, 05:49:26 PM »

Hi Ferp - I agree with your general sentiment.  Although I wouldn't necessarily call neutral prints "over-rated" or "boring", I do prefer a subtle tone and I will very likely go for that when I switch to piezo (probably selenium).

You should be able to simulate selenium in ABW using the color toning wheel in advanced color settings, although expect a lot of trial and error.  That's simpler than a whole new inkset.  I seem to recall that someone once posted some indicative settings for various tonings in ABW. 

You could probably also do it in QTR if you are running color inks, but that would be a lot harder to achieve.  There was an unfortunate typo in my previous post which I have just corrected.  There is a sentence which was supposed to read "Adjusting the toning of a QTR curve is an advanced process and most users would be better advised just to combine two curves".  For selenium toning you'd need to create a whole new QTR curve.

So for that specific toning a selenium inkset might be simplest, but still involves expense and effort.  And I don't see how you could achieve that toning with the new Piezography Pro inkset which only mixes warm and cool - just one axis on the color wheel.
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Stephen Ray

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Re: QuadToneRIP QTR - Unexpected Color Tint
« Reply #24 on: March 25, 2018, 04:12:20 AM »

I agree with others that the three Epson black inks are not neutral.  I'd have said warm rather than green, but it may depend on which generation Epson inkset you're using.  You can see this by examining the "warm" curves that ship with QTR which use only the thee black inks without any colors added for toning effect.

Both ABW and QTR have to add in small amounts of the color inks to achieve a neutral print.  Unlike Mr Rodney, in my experience neither of them is particularly successful.  I find ABW prints at the neutral setting to be a bit cooler than neutral, and for this reason I can usually spot a "neutral" ABW print in an exhibition.  QTR neutral is a bit warmer than neutral.

You can tweak both approaches to achieve a more neutral print.  It's easier to do this in ABW because there is a color toning wheel in advanced color settings, but it's still trial and error process as the on-screen simulation isn't particularly accurate. Adjusting the toning of an ABW a QTR curve is an advanced process and most users would be better advised just to combine two curves.

The added complication, if you're after exact neutral, is the impact of the paper base color.  You may need to tweak for each paper.  Which is one of the complications of Piezography K7 inks.  Many people don't find their neutral inkset as neutral as they claim, even on Hahnemuhle Photo Rag, but with K7 you can't tweak, other than to change to a different paper. 

The Inkjetmall solution to this is their new Pro inkset, which has both warm and cool tonings that you combine to achieve various effects.  So you could achieve an exact neutral, although it may again be trial and error for each paper.  And you lose part of the attraction of Piezography, as you are reduced from seven to four shades on most printers.  But at least you can tweak

I think exact neutral is over-rated and boring.  Find a subtle toning that you like.

+1. Good info here. Could save one a lot of time and expense.
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Alan Goldhammer

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Re: QuadToneRIP QTR - Unexpected Color Tint
« Reply #25 on: March 25, 2018, 08:19:05 AM »

You should be able to simulate selenium in ABW using the color toning wheel in advanced color settings, although expect a lot of trial and error.  That's simpler than a whole new inkset.  I seem to recall that someone once posted some indicative settings for various tonings in ABW. 
Several years ago I worked with Mark McCormick-Goodhart at Aardenburg to look at the various settings of the Epson ABW toning wheel.  I was doing a lot of printing on Hahnemuhle Photorag Ultra Smooth.  there are 10 different settings that were printed out for testing and you can find the permanency tests on the Aardenburg website.  Obviously some of the settings we looked at would not normally be used for B/W printing but it will give users of Epson inks an idea of the stability of the ABW derived prints (with the caveat that the 3880 inkset has been eclipsed by a newer formulation with a more stable yellow ink).
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Paul Roark

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Re: QuadToneRIP QTR - Unexpected Color Tint
« Reply #26 on: March 29, 2018, 03:41:15 PM »

> Just tried printing my first B+W image using QTR and there is a clear green tint ...

My experience mixing inks is that a PK with some cyan in it can be visually darker than a simple PK that is pure carbon.  The cyan is the most lightfast of the color pigments, so putting a little of that in a PK does not weaken it appreciably.  I'm not sure what Epson does, but I've used this approach with some of the MIS inksets that were my designs.  The cyan will give the ink a bit of a green tint in some light.

Paul
www.PaulRoark.com
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Alan Goldhammer

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Re: QuadToneRIP QTR - Unexpected Color Tint
« Reply #27 on: March 29, 2018, 04:44:50 PM »

I'm not sure what Epson does, but I've used this approach with some of the MIS inksets that were my designs.  The cyan will give the ink a bit of a green tint in some light.

Paul
www.PaulRoark.com
This review of the Epson 3800 has a picture of the dot pattern for R=G=B=242 in both the normal and ABW modes.  ABW uses both Cyan and Yellow.  I assume the same pattern is still being used in later model printers.  http://www.outbackphoto.com/printinginsights/pi045/essay.html#20070123  (you need to scroll down about 1/2 way to see the two images)
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