Hi, (Aside from what Rob Day said and going a bit beyond) 1. Whenever possible, work with pictures in RGB (always tagged with an ICC profile, please). 2. When repurposing an InDesign job from one type of CMYK printing to another (with RGB images and natibe elements in CMYK and / or spot colour), always make this two operations in this order: Assign and Convert to final CMYK. (that is from profile CMYK 1 to CMYK 2). Never ever Convert withoust assign first. Why: Because all native elements will change their ink composition and that would include all black texts. 3. If afterwards you see some native elements with an unsatisfiying colour, change the colour swatch they have (because you are using color swatches for everyting, right?). If you do that and you use PDF/X-4 with "Convert to output (preserve numbres)" and the CMYK ICC profile is the real final one (ISO Coated, blah, blah...) and you did your assign/convert before, everything should pass properly to the PDF which would have an appropriated ink limit. But, if you have any pixel of vector element placed in the InDesign file ant it is already defined in CMYK, the situation is different for those elements (not for the rest). Best option is open them in the needed software (Illustrator or Photoshop) and change them to the needed CMYK and ink limit and then update the link in the InDesign file. And, always, open the resulting PDF in Acrobat and chechk that the ink limits are all right).
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