Is there only one Component record for any given item?
If so, do you really need a separate Components table?
If there is never more than one Components record for any given items record, you do not need the portal. You can simply add the field from components directly to your layout.
If there can be multiple components for a given item, base your list view layout on Components rather than items. Fields from Items can then, if you so desire, be used to populate a sub summary layout part to serve as a "sub head" for each list of components.
Either way, the removes the portal and you can use sliding and visibility settings to shrink the field and resize the part to remove unused space when printing/previewing your report.
Key facts about sliding layout objects:
- It's only visible in preview mode and when you print/save as PDF...
- Sliding fields will shrink but not expand.
- All layout objects below and in the same layout part as the slide/resize field need to also be set to slide up and resize.
- Objects in headers and footers will not slide.
- Portals will shrink/slide to fit the number of rows of records, but fields within the portal row will not shrink/slide.
- Fields will slide up only if Top alignment is specified for it and will slide left only if Left alignment is specified.
- Consistent side borders are difficult to achieve with sliding fields.