Hi all,
How do you know the Adobe colors are correct.
in coreldraw - creating spot color - percentage C-100%, M-100%, Y-100%, K-100%
in the name of 400%black
name created.
after publish pdf in coreldraw & check with pdf the separate spot color shown in same. but,
after converting all spot to process(no need to convert spot to process. but, want to know 400% is there)
it comes to 324%. but we want 400%.
but same file designed by illustrator it comes 400% after converting all spot to process
in detail - in illustrator after converting spot colour to process the percentage is same, but CorelDraw differ.
Your problem is Illustrator is converting the 400% colors based on Illustrators color management. In reality everything is working as it should.
Why does someone need 400% CMYK black? That is sheer overkill in most circumstances. Many printing substrates have total ink limits well below 400%. I remember one large format print job with our old thermal inkjet printer where some customer provided artwork had 400% black applied to certain elements in the artwork. The black ink was literally starting to drip across the vinyl when it was rolling thru the printer. Even if the ink hadn't started to run the out-gassing times needed for ink that wet would have been ridiculous. Today we have a pair of latex-based printers and a flatbed printer. For "rich black" we do just fine with a standard CMYK 75-68-65-90 combo or 30-30-30-100.
If I remember the Adobe rich text setting was CMYK 100. This poster does not realize the conversion Adobe is doing is based on the color management settings.
Illustrator has settings under Preferences for the Display of Rich Black and output of Rich Black. A basic 100% K Black can be set to display as Rich Black on screen. A separate setting can allow 100% K to be output as Rich Black. But I think the resulting Rich Black values are going to depend on profile settings. I don't know what setting would result in a Rich Black that pegs all four CMYK values at 100%. In a normal CMYK Illustrator document the max black value that can be picked in the color palette is 74.97%, 67.92%, 67.05% and 90.15%. At least that's what I see every time. A user only gets 100% in all for CMYK inks if he manually types in those values.
I prefer creating my own CMYK-based Rich Black values rather than trusting any kind of auto-settings. The values will depend on the kind of output involved, and if I see anything in print jobs that needs to be tweaked.
No, We are currently working in the R&D department. When customers come for the demo we want to show our full capacity (Overprint and foil height). so, we use 400% black. But, after selling the machine customer no need to use 400% black-100% opacity. But, surely use 400% black in reduced opacity like 50% or 60%.