If your PDF uses RGB colours, it must be converted to CMYK before it can be printed correctly. Here is how to do it — and what to watch out for.
Why RGB Must Be Converted
Printing presses use CMYK inks. When an RGB file is sent to print, the printer converts it automatically — often producing dull, dark or shifted colours. Converting RGB to CMYK yourself gives you control over the result.
Method 1: Convert in Design Software
This is always the preferred approach:
- Adobe Photoshop — Image → Mode → CMYK Colour. Review and adjust colours before re-exporting.
- Adobe Illustrator — File → Document Colour Mode → CMYK. Edit colours as needed, then export.
- Adobe InDesign — Set document colour mode to CMYK in Document Setup before placing images.
After converting, always proof the colours on a CMYK-calibrated display or request a print proof.
Method 2: Automatic PDF Conversion
If you only have a PDF (no original design file), use PrintFix247 or PrintConvert247 to convert the PDF from RGB to CMYK automatically using a professional ICC profile.
Convert your PDF to CMYK automatically
Upload your file and get a print-ready CMYK PDF in seconds.
Convert to CMYK →Colour Profiles Matter
The most common CMYK profile for European offset printing is ISO Coated v2 (ECI). For uncoated paper: ISO Uncoated. Using the correct profile ensures your colours are optimised for the paper type and printing process.
Check After Conversion
After converting, verify the result with PrintReady247 to confirm the file is now fully in CMYK mode.