Apple Final Cut Pro 6 - Manual (Page 1460)

Chapter 29 Rendering and Video Processing Settings 675
IV
2 Click in the Remove column to delete specific render files.
 Clicking an item that includes other items, such as a project, automatically includes
all those items within it.
 Clicking a sequence selects all the render files for the sequence.
A checkmark appears next to each item you want to delete. The total amount of disk
space that will be made available is displayed at the bottom of the dialog.
3 When you’re ready to delete render files, click OK.
All files tagged for removal (with a checkmark) are deleted from the scratch disk.
Important: Deleted render files cannot be restored with the Undo command.
Preserving Render Files
When you make changes to effects, composited media, and other edits that have
already been rendered, the render file for the affected item is no longer valid.
 If the project has been saved since the render file was created: The render file is deleted
when whichever of the following happens later:
 The project is saved again.
 The change falls off the “Undo queue” (the series of changes that can be reversed
with the Undo command in the Edit menu).
 If the project has not been saved since the render file was created: The render file is
deleted when the new change falls off the Undo queue.
You can keep your important render files by nesting sequences.
Using Nested Sequences to Preserve Render Files
You can preserve render files for a sequence or for audio clips within a sequence by
nesting that sequence within another sequence. Nesting is particularly useful for
protecting the render files for effects-intensive clips you plan to trim frequently.
For detailed information, see Volume II, Chapter 23, “Sequence-to-Sequence Editing.”
Disabling Tracks Affects Render Files
When you disable a video or audio track in the Timeline, any render files associated
with that track are lost. If this happens, you can restore that track’s render files by using
the Undo command.