About Flattening and Normalizing

Dependencies between flattening and normalizing

To ensure reproducible results, there are some technical dependencies between flattening and normalizing.

If Flattening is used, all images, vector and text objects in the PDF will be normalized to the same CMYK color space. Therefore, normalizing must be activated for the RGB color space. This is necessary because a PDF can have overlapping objects in different color spaces, for example, an RGB object on top of a CMYK object. These color space mismatches need to be resolved during flattening, as the new object created from the overlapping region can only be in a single color space.

Spot color channels can be preserved and color managed separately from the process colors. If flattening is used, spots can also be converted to CMYK. This limitation helps to avoid undesired effects, because the visual impression of stacked objects might be changed dramatically when overprinting spot colors are converted to CMYK.