The file 'Parametric Circa/Disk-bound Cover Or Bookmark 3D Printer Model' is (stl,scad) file type, size is 33.9KB.
I actually made this so that a calendar would have a hangar, not as a book cover, but it generalizes pretty well to book cover and bookmarks, especially with the custom top offset.
Included files:
.scad
filecalendar-hanger.stl | 86.6KB | |
half-letter.stl | 86.6KB | |
parametric_circa_cover.scad | 1.3KB | |
top-tab-bookmarklet.stl | 22.2KB |