Color shift of profile patch sheets

[Ink stained Fingers]

What are the maximum deviations and what colors are affected?

It's a red spot with 1.61 and a green spot with 1.60.

Yes, you can scan patch prints almost instantly - lots of papers are of a kind of instant dry.

Especially cast coated papers showed sometimes a big shift in the darks, also cheap RC papers.

I have observed this as well that the black point is drifting around for a while on some papers. It all comes down to the question how much accuracy you want to acheive , we are talking here about small variations which may not be visible at all in prints , even in direct comparison

 

[The Hat]

we are talking here about small variations which may not be visible at all in prints , even in direct comparison

That was my question too, is there a visible difference to the naked eye..

 

[Artur5]

This is a case by case situation (different papers, inks, light conditions etc ).
A simple practical test : compare side by side two copies of the the same image. One of them printed two minutes ago, the other made 24 hours earlier and search for subtle differences.

 

[The Hat]

What I was interested in was, if you proceed with your profile after 3 hours of drying time and you then make another profile after a week from the same scan, then make two prints, is there any visible difference in these two prints..That's the litmus test...

 

[Ink stained Fingers]

This is a case by case situation (different papers, inks, light conditions etc ).

It's as always - it depends-----I wouldn't expect visible differences anymore between prints with profiles created after 3 hours or 1 week of drying time, the most drift happens within the first hour or so, and some more with black and colors close to black in some cases.

@Keith Cooper has given some good advise what to look for in (his) test images - color balance - saturation smoothness/uniformity and specific points with B/W images

https://www.northlight-images.co.uk/printer-test-images/#colour_printer_test_images

And it all depends on your viewing conditions - e.g. daylight - a possible effect of UV brighteners , and there is a very personal factor as well - your ability to discern colors e.g. red vs. green in images.......

It's just a simple question when creating profiles - with ColorMunki or i1 software - why shouldn't I wait with the patch sheet scan till the next day to avoid some color shifts - it's for free to improve the overall correctness of a profile for a given paper , there are additional factors like long term drift, UV/OBA compensation which cannot be controlled that easily.

 

[The Hat]

why shouldn't I wait with the patch sheet scan till the next day to avoid some color shifts -

So your saying, so long as you profile, whether its waiting 3 hours or a week, the results will be the same regardless of paper type used, and doing it this way guarantees the very best results every time.. I can see now why it’s necessary when its explained correctly..

 

[stratman]

From the International Color Consortium (ICC) White Paper #3, ICC Recommendations for Color Measurement:

"Furthermore, time should be given to ensure that the print is properly dry before
making measurements."

That's all.

https://www.google.com/url?sa=t&rct...surement.pdf&usg=AOvVaw3TrPUwC3HGJxbhLbPNVEJ-

 

[stratman]

Going back to a link I posted earlier from Paul Lindstrom of Digital Dots, no slouch with color management, discussing when to profile a freshly printed target:

A third complication is to define what the target values should be for
the press operator, when measuring at the press seconds after the paper
sheet comes out of the press. At this point the inks can be considered as
still being wet and the appearance of the colour will change during the
drying process. The colour change is by its nature greatest in the early
stage of the drying phase, usually during the first hour, but prints should
not be considered fully dry and colour stable for the first 24 hours. So
the dilemma for the press operator is that the colours wanted by the de-
signer, and that can be measured on a colour sample, are very different
from when measuring recently printed wet sheets.

https://www.color.org/events/frankfurt/Lindstrom_ICCFrankfurt2013_Spot_Col_Proofing.pdf

 

[Ink stained Fingers]

So your saying, so long as you profile, whether its waiting 3 hours or a week, the results will be the same regardless of paper type used, and doing it this way guarantees the very best results every time..

Yes

 

[Ink stained Fingers]

Another 4 weeks are gone since the last scan of the profile patch sheet, I scanned it again now after 4 weeks, so it's 5weeks in total since the original print (with Epson 106 inks)

_____________deltaE
1 h to 3 h____0,30
1 h to 8 h____0,52
1 h to 1 d____0,70
1 h to 1 w____0.98
1 h to 5 w____1.67

it shows that the colors are further shifting, the patch sheet is kept in the dark and dry in a PE sleeve.