At this point I recalled some
very short advice by Wilfried, stating that trusting Colorsync always had produced acceptable results for him.
Now, this for me represents a murky area. So far, Colorsync had mostly appeared as a nuisance when opening documents in Photoshop or Illustrator, the computer screaming incessantly about an embedded color profile this, and another one that did not match the color profile of the document, and what did I want to do? Mostly I just OK'd what the programme suggested by showing one button of two or three as being checked.
Obviously, this was not the way to treat Colorsync. Following Wilfrieds hint, I looked through the computer's tool programmes, and certainly, there was something called "Color Sync tool". That, however, seemed far above my competence and furthermore did not seem to contain any serious adjustment options at my level.
So I searched, and read up on what Color Sync really is. Turns out it's a very useful thing. By allocating what's called a color profile to each document, the idea is that the color management will be appropriate throughout a chain of applications, such as a camera, a computer, an application, and a printer.
To do this, however, it is essential that Color Sync is allowed to do so uninterrupted. Which means it should be turned on, of course. Which I hadn't for my printer, since I believed that I could do a better job manually than the computer. Which I couldn't.
So the next and final step for the printer was to turn Colorsync on. Which automatically disabled all those "Advanced" controls I had been fiddling with in vain. From now on Colorsyn would do the job. The only option left for me was to choose between three different profiles for the printer - one "Epson IJ printer", one "sRGB IEC something", and one "Automatic". I printed test copies of all three:
Since I could not discern any difference between them, I set the setting to "Automatic" for now. What matters is that the prints were good, better in fact than anything I had achieved so far. And the means to get there was to leave Colorsync on and do nothing about color correction more than that!
Thank you, Wilfried!