Converting CMYK Blacks to 100% K....

[kdw75]

Some of the files we receive in PDF format consist of a solid black background with some artwork on it. The file is apparently set in photoshop and then saved as a PDF. Against all our recommendations their designer refuses to save anything as vector data. It is all rasterized then saved as the PDF.

The black though isn't pure black. It is around 88% K with random percentages of CMY. This comes out rather brown and muddy rather than pure black.

Does this sound like the designer is starting in RGB and then converting to CMYK? More importantly is there any method of converting the black into pure 100% black or does the fact that it is a raster image make that impossible?

 

[Joe Duffy]

If you have PitStop or PDF ToolKit you can do this quickly.

 

[kdw75]

No we do not. We have Acrobat 10 Pro. We are looking at getting something that would help. I had looked at flightcheck. Most of our problems are with customers PDF files.

 

[Joe Duffy]

Contact Enfocus and get a demo version to test.

 

[saburnsjax]

What type of printing equipment/drivers are you using? Many systems, especially if they have a fiery controller, have options such as "black detect" or "use pure black" that are very good at cleaning up most files...

 

[kdw75]

We are printing some to a xerox 7760, where we want black only, and others to a Harlequin RIP. On the press the black isn't too bad. Just a little muddy looking. Certainly sellable.

 

[DanRemaley]

Change the color settings in Photoshop to “maximum GCR” then open the pdf file and save as new pdf. All undercolor will be removed.