RGB 0,0,0 in images print as gray, KM C65hc

[intryck]

I'm about to run a job consisting of an image with a black background and the area around it has been filled with black. Using acrobat I can see both areas are 0,0,0 RGB but in print the image-black comes out as gray and the added black comes out as 100% black.

I tried converting the document to CMYK but that ended up with 99/40/20/98 mix which prints blue.

Is there any way I can force my Fiery rip to always turn 0,0,0 RGB to 0/0/0/100, regardless whether it's in an image or a path?

 

[ericmadsen]

Have you tried using 'Absolute' rendering intent for RGB under Expert Color in the CWS job? I'd mess with the settings there... you can make RGB black print as black instead of gray for sure. Fiery does do color substitution, but not within raster images.

In RGB preview mode in Acrobat, both CMYK black and RGB black would misleadingly appear as 0,0,0 even if the fill in the PDF file is CMYK. So make sure your source app is forcing RGB when creating the PDF.

If that doesn't fix it, you could re-build the image in CMYK with the black as K black. Or, you could increase the canvas size of the image, and build your fill there.

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[mattbeals]

I'm about to run a job consisting of an image with a black background and the area around it has been filled with black. Using acrobat I can see both areas are 0,0,0 RGB but in print the image-black comes out as gray and the added black comes out as 100% black.

I tried converting the document to CMYK but that ended up with 99/40/20/98 mix which prints blue.

Is there any way I can force my Fiery rip to always turn 0,0,0 RGB to 0/0/0/100, regardless whether it's in an image or a path?

Callas pdfToolbox can easily fix this. Download a trial version and process your job. I can help if you need. The demo is fully functional and won't watermark your job. Give it a shot!

 

[UberTech]

I'm about to run a job consisting of an image with a black background and the area around it has been filled with black. Using acrobat I can see both areas are 0,0,0 RGB but in print the image-black comes out as gray and the added black comes out as 100% black.

I tried converting the document to CMYK but that ended up with 99/40/20/98 mix which prints blue.

Is there any way I can force my Fiery rip to always turn 0,0,0 RGB to 0/0/0/100, regardless whether it's in an image or a path?

In colourwise, spot colour there is an option called 'substitute colour'. Enter RGB values and then the required CMYK output.

 

[ericmadsen]

UberTech, I thought the Fiery documentation said that option only works for vector images. The OP is wanting to substitute colors within a raster image... am I wrong that this won't work for that?

 

[UberTech]

Yes you are correct, my bad, half reading.

 

[Lukas Engqvist]

A color server would do that. May be that you can get the same effect by using acrobats convert colour to convert to a Max GCR ICC profile and check the keep black option. If it is just one or two images you can right touch up in photoshop and do a replace colour of channel mixer after selecting appropriate area.

 

[intryck]

Funny, I managed to fix this myself - under color management I changed "Gray & Black" RGB from none to Text/Graphics/Images and the print is now in the same, black color all over.

 

[mattbeals]

It really sounds like you want your RGB grays and blacks to be in device gray so that the imaging unit does not screen non-device gray blacks. Again, this is easy to do with pdfToolbox so that the values in come out at the same values in device gray. No fancy work, no color servers, just an effective tool for the problem.