Hi Lagarto thanks for your reply. I hope I understood.
If I understand correctly you have created a new profile with custom black generation and then you have imported it into Affinity, correct? Or have you managed to edit an existing one in Affinity?
My aim is related to production of illustrations. I give an example.
I have a line-only drawing that I scanned. The drawing was scanned in grayscale. I need to convert to cmyk to color it. I may find myself having to choose in case A or in case B.
Case A: I want the line not to contain black in the black channel, only cmy> I customize black generation in 'none'. When I convert from grayscale to cmyk I have the black channel empty.
Case B: I want the line to be composed only of black, and nothing in cmy> I customize the generation of black in 'maximum'. When I convert from grayscale to cmyk I will have my line only in the black channel already at the correct intensity and the cmy channels are empty.
Both are correct as it depends on what I want to achieve.
When I want to work without black I need 'none' black generation because otherwise some processes would automatically add black that I don't want (filters, color wheel etc).
I could adjust my illustration later with curves, but the result would change from what I had set and it is not possible to have control (it is very difficult to explain this).
The speech is different when working with photos because a little black is right to give depth and make the photo better. The amount of black is also very important in a photo because it can make the result better or worse. It is always interesting to experiment with various types of customization because one result can be better than others. It really depends on the photo.
With curves it is impossible to compensate for the absence of black, in the sense that the result will never be the same as the photo that contains black, because the "black" composed of cmy100 is different from the k100. But if you deliberately choose not to want black in the channel it is because you want to have something 'different' specifically for your purposes. In publishing, the choice k none is wrong. In the artistic field, everything is allowed as long as there is a purpose and an intent.
This is according to my personal experience with illustrations. My experience with photos is limited and unprofessional.
For my needs it is very important to have the black control during the profile conversion phase
Sorry if I've written a lot
Thank you for your support
Thank for image very interesting and demonstrative 👍