For RSE half folios, the smaller trimmed image was simply mounted in the center of a blank full folio sized card, still with no text of any kind in the margins of the card.
SE half folios were treated substantially differently. A black, open-faced title was printed below the half-folio print, followed by text which described that image. On the back of the same page additional text would appear describing the next full folio image, such that the pages could be bound, alternating half and full folios, with descriptive text appearing opposite the full folios. The choice was made not to print any text on the back of the full folios, however, so that a blank page would face each half folio. At right are two images of a bound volume showing the result. At top is seen the SE half folio of Side View of the Great Sphinx, showing the blank facing page, which is actually the back of a preceding full folio. Below right, the half folio page has been turned so that the text on the back of the Side View of the Great Sphinx half folio now faces and describes the next full folio print The Great Sphinx, Pyramids of Gizeh.
A closer view of the Side View of the Great Sphinx shows the publisher's mark just below the image, and the typical half folio black open-faced title (see below). Occasionally the accompanying text was printed on separate pages, rather than below and on the back of the half folio images, but this is relatively rare. The SE proof edition sometimes displays the same publisher's mark immediately below the image, and sometimes not, but never displays block letter titles on either the full or half folios.
The Publisher's Mark and Title area from an SE half folio
Titles and Text