Adobe InDesign CS3 - Manual (Page 470)

INDESIGN CS3
User Guide
463
Maximizing trapping performance
Whether you use Adobe In-RIP trapping or built-in trapping, you can save time by not processing pages that don’t
need trapping, such as pages containing black text only. You can use trap presets to enable trapping only for the page
ranges that require it.
The speed with which built-in trapping is accomplished depends on the speed of your computer system. If you’re
trapping every page of a long document, use the fastest computer system you have. Built-in trapping also makes
extensive use of your computer’s hard disk, so a fast hard disk and data bus will benefit the built-in trapping engine.
To maximize the time your computers are available for other tasks, consider using Adobe In-RIP Trapping, which
processes all traps at the RIP, instead of at your computer.
Setting aside disk space for built-in trapping
To trap the edges of every color that requires trapping, the trapping engine creates a large number of paths that are
used only by the output device (the paths are not stored in your document). While Adobe In-RIP Trapping processes
and stores these additional paths at the RIP, built-in trapping uses your computer’s hard disk as a temporary storage
area for these trap paths. Before you use built-in trapping, make available as much hard disk space as possible.
The amount of disk space you’ll need depends on a wide range of factors, so it isn’t possible to predict exactly what
a particular trapping job will require. However, disk space requirements are most likely to increase when one or more
of the following characteristics of your document increase:
• Number of pages included in trapping page ranges.
• Number of overlapping color objects.
• Number of images that need to be trapped.
• Amount of text that needs to be trapped.
• Resolution of final output.
If the processing of a job that uses built-in trapping is interrupted or exhausts your disk space, trapping data may be
left behind on your hard disk. When necessary, you can exit the application, and then find and delete temporary data
in the C:\Temp folder (Windows). In Mac OS, restart your computer.
Trap a document or book
Do not change the default trapping settings unless you’ve consulted with your prepress service provider, and you
understand how trapping options work in the context of your specific document and printing conditions.
When trapping multiple documents in a book, make sure that you assign any custom trap presets to page ranges
within the individual documents of the book. You cannot assign trapping settings to an entire book at once. However,
you can resolve conflicting presets in a document.
1 If necessary, create a trap preset with custom settings for your document and press conditions.
2 Assign the trap preset to a page range.
3 Choose File > Print to open the Print dialog box.
4 Select Output from the list on the left.
5 For Color, choose either Separations or In-RIP Separations, depending on whether you’re creating on-host or
in-RIP separations.