Operation Manual

588 | Corel DESIGNER X7 User Guide
7 Change any of the following settings:
• Screening technology
• Resolution
• Basic screen
• Halftone type
You can set the screen frequency, screen angle, and overprint options for spot colors as well as process colors. For example, if you
have a fountain fill made up of two spot colors, you can set one to print at 45 degrees and the other at 90 degrees.
Working with color trapping and overprinting
When colors are trapped, they are intentionally overlapped so that misalignments of print separations are not noticeable. In manual
trapping, one color must overprint the other. Overprinting is achieved by printing one color over another. Overprint trapping works best
when the top color is much darker than the underlying color; otherwise, an undesirable third color may result (for example, cyan over yellow
results in a green object). In some cases, you might actually want to create a third color; for example, you can overprint two spot colors to
create a third color.
How overprinted colors mix depends on the type of colors and ink you are mixing and the types of objects you are overprinting. For example,
an object that uses a CMYK color overprints differently from an object that uses a spot color. Bitmaps also overprint differently from vector
objects. You can preview a simulation of how overprinted colors will mix by enabling the Enhanced viewing mode and the Simulate
overprints viewing mode. For more information about choosing a viewing mode, see “Choosing viewing modes” on page 71. Some
variation between the preview and the printed version may occur, depending on the printer you use.
When you are ready to print, you can choose to preserve overprint settings if you want to trap objects in a document, or if you want to mix
the overlapping colors for effect. You can also choose to knock out the overprinted areas so that only the top color is visible. If you want to
print a proof version of the file, you can simulate overprints. Simulating overprints rasterizes the file, and it prints using process colors only.
You can set a group of objects to overprint. You can allow text to overprint overlying objects. You can also overprint bitmaps; or each vector
object’s fill, or outline, or both. In addition, you can overprint specific color separations and specify in which order they will print, as well as
whether you want to overprint graphics, or text, or both.
The two methods for automatic color trapping include always overprinting black and auto-spreading. Overprinting black creates a color trap
by causing any object that contains 95% black or more to overprint any underlying objects. This option is useful for artwork containing a lot
of black text, but it should be used with caution on artwork with a high graphics content. You can adjust the threshold, if the print service
provider recommends a black threshold value other than 95%.
Auto-spreading creates color trapping by assigning an outline to an object that is the same color as the object’s fill and having it overprint
underlying objects. Auto-spreading is created for all objects in the file that meet three conditions: they do not already have an outline, are
filled with a uniform fill, and have not already been designated to overprint.
For advanced trapping options, see “Specifying In-RIP trapping settings” on page 590.
To preserve or ignore overprints when printing
1
Click File Print.
2 Click the Color tab.
3 Choose one of the following options:
• Print composite
• Print separations
4 Click one of the following tabs:
• Separations
• Composite
5 From the Document overprints list box, choose one of the following options: