Difference with printing CMYK document

[RV-95]

I am a beginner and in the process of designing a document in InDesign. To my document I want to add an image that has been edited in Photoshop. I have converted the image to CMYK colors and saved it. In both Photoshop and InDesign, I have set the color profile U.S. Web Coated (SWOP) v2. However when the photo is added to InDesign, the color black varies greatly. What am I doing wrong?

[rob day]

Hi @RV-95 , Will your document be printed on a commercial web offset press? Offset inks are somewhat transparent, so the appearance of black ink by itself—the default InDesign [Black] Swatch—will be different than Black plus CMY. You can use InDesign’s Separation Preview panel to check a black’s output percentages.

[RV-95]

Yes eventually it will indeed be printed by a commercial press. I also tried to keep the black of InDesign the same throughout, then added an image with a transparent background. But then when converting to PDF a more red color is created. In fact, I want to show the document for review first. Or am I totally messing it up this way?

[rob day]

You can make CMYK conversions in Photoshop, but it will be more efficient and less error prone if you place profiled RGB images and make the conversion to CMYK on a PDF Export.

Here you can see by default InDesign soft proofs the difference between Black only and Black+CMY. An RGB black will convert to the document’s CMYK profle’s black point:

An Export to PDF/X-4, which is a preset designed for offset printing, with the Destination set to DocumentCMYK:

In AcrobatPro the Output Preview’s Object Inspector shows the RGB color has been converted to DocumentCMYK—US Web Coated SWOP in this case. The Acrobat preview defaults to the PDF/X Output Intent: