puzzling colors when printing rectangles with color handling set to "performed by printer"

[nick l]

Added note:  This reports on a discrepancy between the printing of rectangles filled with gradient vs plain fill when color handling is set to "performed by printer"  At the end of my second post below, I point out that the problem might lie with the color of the plain filled rectangles rather than with the color of the rectangles filled with a gradient.  The remainder of this post is the original post.

In trying to figure out how to get my printer to print the colors I want, I tried all sorts of arbitrary combinations of settings in the Affinity Publisher 2 print dialog (to get a sense of what effect they have).  I stumbled across an odd behavior.  After various experiments, I created the following test case: Create a rectangle pair by putting 2 rectangles next to each other, setting the fill of one of them to some rgb parameters.  The fill of the other is then set to a linear gradient, both ends of which are exactly the same rgb values, so that both rectangles appear to have exactly the same fill.  Then print them with color handing set to "Performed by Printer" but with the printer color profile set to something different from the document profile. I got strange results printing to an Epson EcoTank 4-ink printer (with its properties set to "no color adjustment") and also strange results printing to PDF with "Microsoft Print to PDF".  In  some cases the colors of the rectangles that are specified with gradient fills differ in the printout or PDF from the colors of the rectangles that look exactly the same, but whose fill is specified without a gradient.  To me, this suggests a problem in Affinity's color handling that might also be causing other problems.

I am including:

• a sample afpub file
• a jpg created by scanning a printout created by my Epson Ecotank ET-4850 printer (labeled with a caption)
• a sample pdf printout from the sample afpub file (modified only to add a caption)'
• a jpg file exported from a combination of pdf files created with several printer profiles

gradient test d.afpub gradient test d adobe.pdf

Edited October 22, 2023 by nick l
added clarifying note at beginning

[nick l]

A bit more context:  I've been trying to make a mental model of what's going on in mapping colors from their representation in the affinity files to the amount of the different inks used for each pixel by the printer.  I've been having trouble finding relevant info at the level of detail I'm hoping for.  I've tried various experiments.

1.  I've been conjecturing that the mapping is strictly pixel based, that is, that the mapping for a given pixel depends only on that pixel's color and not on the colors of neighboring pixels (or any other pixels).  I would expect that in the two cases that differ surprisingly in the above report, the pixel values for the gradient-filled rectangles and the non-gradient filled rectangles would be identical (they are specified to be identical and appear identical when displayed in affinity publisher). Thus I would expect that there would be no possibility that they could print differently.  This is clearly wrong.  What is really going on?
2. In trying various combinations of parameters to see what effects they might have, I've tried the "color handling performed by printer" and "color handling performed by app" settings in combination with setting the EcoTank printer's color correction setting to either "no color adjustment' or "color controls" with color mode set to Adobe RGB gamma 1.8 (with no further tweaks).  For a given EcoTank color correction setting, in the limited tests I've done, it makes at most the slightest difference whether the color handling setting is set to "performed by app" or "performed by printer" - except for the case described above involving rectangle fills.  The uploaded pictures with this post include a band with a gradient.  There are 3 rectangles: a plain one on the left, another plain one on the right, and a gradient filled one in the middle going from the left color to the right color.  When changing from app to printer color handling, the changes occur in the plain rectangles on the left and right, not the gradient filled rectangle in the middle (see the picture where I cut and pasted the two together).  (Both the uploaded images in this post are scanned from EcoTank prints.)

[nick l]

What *is* the difference between color handling "performed by app" and "performed by printer"?  I just got some Red River Polar Matte paper, and have made some test printouts on that paper, using their color profile for that paper and my printer.  I've tried the 4 combinations:

1. color handling performed by app, and the printer properties color correction set to no color adjustment
2. color handling performed by printer, and the printer properties color correction set to no color adjustment
3. color handling performed by app, and the printer properties color correction set to color mode: adobe RGB gamma 1.8
4. color handling performed by printer, and the printer properties color correction set to color mode: adobe RGB gamma 1.8

I'm uploading scans of the printouts made by my Epson EcoTank printer.  The color correction settings in the printer properties dialog have a big effect, and the choice of app or printer makes a clear difference to the rectangles. The effect on the images seems very subtle.  The text at the top is copied and pasted from screen captures, and might look slightly different between the app and printer settings.  I'm not able to discern any clear difference between app and printer settings  in the printouts of the jpeg photo images.

[Dan C]

Hi @nick l,

Thanks for your report and our apologies for the delayed response here!

I just wanted to inform you that I have escalated this issue internally and our team are investigating this further.
I will be sure to respond here as soon as possible with our findings.

Many thanks for your continued patience and understanding 

[nick l]

Thanks very much for responding.  I understand that this may not be a priority.  It sounds like people have had a variety of problems with printing.  I would love to have a clearer picture of the process involved in going from my RGB document to the inks of my CMYK printer. But there are so many issues....  My hope with this report is that it at least gives an illustration of what appears to be a concrete problem (or two....)  Meanwhile, until further notice, I'm just setting color handling to "performed by app".

[Leigh]

On 10/30/2023 at 5:06 PM, nick l said:

Thanks very much for responding.  I understand that this may not be a priority.  It sounds like people have had a variety of problems with printing.  I would love to have a clearer picture of the process involved in going from my RGB document to the inks of my CMYK printer. But there are so many issues....  My hope with this report is that it at least gives an illustration of what appears to be a concrete problem (or two....)  Meanwhile, until further notice, I'm just setting color handling to "performed by app".

We're still looking into this but it looks like Red River Paper advise to use "Performed by App" with their Printer Profiles: https://www.redrivercatalog.com/profiles/how-to-use-inkjet-printer-profiles-affinity-photo-windows.html

Still doesn't explain why the gradients in the original post are changing colour - will get back to you on that.

[Leigh]

Just wanted to let you know that i've been able to replicate what you're seeing. I'm going to ask our developers for clarification on how it should work - when I have an update I will let you know. Please be aware that we're heading into our annual Christmas closure so I might not be able to provide an update until the New Year.

Out of curiosity, what happens if go to Rasterization and enable Rasterize Entire Page within the Print settings before printing? I'm finding the issue is related to how vector objects and raster objects are being handled.

[Leigh]

Just wanted to post a quick update on this. Our developers have confirmed that it's a bug and will be fixed in an upcoming update.

Thanks for letting us know.

[Affinity Info Bot]

The issue "Undesired Colour Conversion when using 'Performed by Printer'" (REF: AF-1633) has been fixed by the developers in internal build "2.5.0.2375".
This fix should soon be available as a customer beta and is planned for inclusion in the next customer release.
Customer beta builds are announced here and you can participate by following these instructions.
If you still experience this problem once you are using that build version (or later) please reply to this thread including @Affinity Info Bot to notify us.