Which font has the least width?

Which font has the least width?

When you put a book in shelf.
You can see the book from the view that you can determine the diameter of book

I really do’nt know what is the name of that view , But I need font for that

Which font do you suggest?

errr, what? Maybe you should ease off the whisky for a bit. Just kidding

just to try and clarify what you’re asking for…
are you looking for suggestions for a font to use on the spine of a book?..the vertical edge?..or as you said, the part of the book that is visible when placed on a bookshelf.

if so…
typically, you’d use the same font(s) that you’re using on the front cover of the book.
if you need something less wide, maybe try to see if that font you’re using has a condensed or narrow version?

I mean spine of book.