As in the title: can we create additional lines in the
showframe option from the package
geometry in order to create a new frame that suits our needs?
Essentially I am looking for a way to see how I am setting a cover page for a book. That is, I have frontcover, backcover, and spine all on the same page set with
geometry (hence, it looks like a landscape page).
The problems is that I would like to see where the spine and where all margins (left, right, top, down) are in order to see how to properly compose the page.
PS: Observe that there is a question around where it is explained how to modify
geometryto behave properly with the landscape option, but that does not work here, since I did not set it landscape.