If the caption is placed on either side, it's often best to change the alignment of the title, comment, counter, and metadata from the default center to right or left (caption on the right, align the text to the left, for example).
Using side-loaded captions requires some consideration of page width. If images are scaled to 640px wide, the caption is 150px and is placed on either side, and the image is centered, the page width (including image borders) can easily exceed 1000px. Bear in mind that many laptops have monitors that are only 1024px wide, so a page that's wider than that will produce horizontal scrollbars. The largest page width in an album can be determined by opening the system console (F7) after the album has been generated - the skin places a message in the console that indicates the size of the widest slide page.
Because of these changes, opening an existing project will result in the selection of default values. The Overlay and Text » Overlays tabs should be checked before making the album.
The overlay's position, inset from the thumbnail image corner, color, and background color may be chosen on the Overlays tab. The text that is displayed, which defaults to NEW, is set in the skin's texts.properties file. Its size and style can be adjusted under Fonts » Index Page. When a visitor hovers on the "New" icon, the popup tooltip shows the date on which the image was added - for a folder, it shows the date on which the most recent image was added to that folder. The tooltip prefix, which defaults to Added:, is set in the skin's texts.properties file. The date format is taken from the jAlbum setting under Album » Settings » Advanced » General.
This feature does not replace the existing routine for using external files to insert material - topinfo.txt, bottominfo.txt, htmlhead.inc, header.inc, and footer.inc. It is offered in addition to that capability. Using external files makes more fine-grained control possible, adding material to some folders but not others, for example. Placing material in these new tabs is more convenient, and easier to maintain, but presents fewer options (all folders, or just the top level). It is recommended that, in a given album, you use one method or the other, but not both.
jAlbum is a bit stubborn about remaking thumbnails. If you have an existing project in which jAlbum applied its own "film" icon to the thumbnails, but want to switch to the Gromit video overlay, the quickest fix is to open the Output Directory and delete the thumbs subdirectory. Then, a Make Album will create new thumbnails without the jAlbum "film" icon. Similarly, if you decide you want to go back to the jAlbum icon, turn off the Gromit option for video overlays, delete the thumbs subdirectory from the output, and Make Album again.