Unfortunately, the Slideshow module cannot automatically wrap text. Therefore, if you have entered a long caption and want to display that caption under an image, the text will (more than likely) end up being truncated – unless you scale the caption really small. To avoid this, insert your own line breaks (in the Caption field in the Metadata panel) using Option + Enter (Mac), Ctrl+Return (Win).

Hi Julieanne,
could it be that you meant “Ctrl+Return” instead of “Alt+Return”?
On my windows 7, LR 3.5 64 Alt+Return does not work, but Ctrl+Return does the job.
Thanks
Sven
Thank you for catching this and pointing it out! I am not near a Windows machine right now to test but I have corrected my original post…
Trying to do a multi-row identity plate in LR4, Windows 7. Enter or Ctrl-Enter saves the plate, but doesn’t drop to the next line. Is there a way to do this? Thanks.
You would have to create the multi-line Identity Plate as a graphic. You can not have a multi-line get Identity Plate.
Is there a way to change line spacing for multi-line Captions in the Slideshow module? The default line spacing is too great for my liking, taking up too much real estate on the image. Thanks
No, you can not customize the line spacing but it’s a great feature request – can you post it to one of these sites so that the correct eyes see it? Thanks!
http://forums.adobe.com/community/lightroom
http://feedback.photoshop.com/photoshop_family