Color conversion and ink management, About color conversion – Adobe Acrobat 9 PRO Extended User Manual
Page 471
465
USING ACROBAT 9 PRO EXTENDED
Print production tools
Last updated 9/30/2011
By default, when you print opaque, overlapping colors, the top color knocks out the area underneath. You can use
overprinting to prevent knockout and make the topmost overlapping printing ink appear transparent in relation to the
underlying ink. The degree of transparency in printing depends on the ink, paper, and printing method used.
Rich Black
Indicates areas that print as rich black—process black (K) ink mixed with color inks for increased opacity
and richer color. Rich black is used for large areas since you need the extra darkness to make the text look black rather
than gray.
Type the Start Cutoff percentage to define the minimum percentage of black to diagnose the content as rich black. Rich
black for this warning is a percentage of black (based on the cutoff value) and any nonzero C, M, or Y.
To change the warning color used in the preview, select a color from the swatches color picker.
More Help topics
View information about the content of a PDF document
Use the Object Inspector dialog box to view image resolution, color mode, transparency, and other information about
the content of a document.
1 In the Preview section of the Output Preview dialog box, choose Object Inspector.
2 Click in the document window to view information about the objects that are under the pointer in the Output
Preview dialog box.
Color conversion and ink management
About color conversion
Colors must often be converted when they are displayed on a monitor or sent to a printer. Conversion is necessary
when the color models do not match (for example, when CMYK color is displayed on an RGB monitor, or when a
document with images in an RGB color space is sent to a printer).
Acrobat uses the source color spaces of objects in a PDF to determine what (if any) color conversion is required, for
example, from RGB to CMYK. If a PDF contains objects with embedded color profiles, Acrobat manages the colors
using the embedded profiles rather than the default color spaces. For images and other objects in the PDF that contain
embedded color profiles, Acrobat uses the information in the profile to determine how to handle the appearance of the
color. For objects with managed colors (those with embedded color profiles), this conversion is well understood.
Unmanaged colors, however, do not use profiles, so one must be temporarily used for the purpose of conversion. The
Color Management panel of the Preferences dialog box provides profiles for converting unmanaged colors. You can
also select specific profiles based on local press conditions.
For a video on converting colors in a PDF:
.
More Help topics