Why is flattening required prior to Color Management?
Color management can only be applied to single PDF elements and not to the resulting color of a PDF page.
The answer to color errors due to Transparency and Overprint? – Flattening
Merge PDF elements that have special painting rules such as transparency effects and overprints.
After flattening, all special painting rules are removed by merging the related elements.
Advantages of Flattening:
• All special painting rules are removed – it is safe to apply Color Management
• Element structure is re-organized and sometimes fixes errors
Disadvantages of Flattening:
• The PDF becomes more complex because of more elements
• PDF size sometimes increases dramatically
• Some editing capabilities might be gone (e.g. text)
• Total processing time increases – Flattening takes time and additional elements have to be treated during Color Management
• Errors in Adobe PDF Library concerning Flattening