A book page has three margins outside top bottom and a gutter the inside margin where the pages are glued or sewed together.
Book layout gutter.
In page layout the gutter is a slightly larger margin added to the inside edge of the page.
This could cause issues further on as the gutter margin is the amount of space between the content of your book and the fold where the pages of the book will be bound together.
Imagine a novel with text disappearing into the binding.
By default the gutter margin will be set to 0.
A gutter is the section of the page that leads into the binding of perfect bound books and hard cover books.
Keep that in mind when laying out your book page.
The outside margins give room for the reader s thumbs when they hold the book.
Gutter margin margins are the blank spaces around the type area on a book page but the inside margin has the special name gutter and it is always the margin on the bound edge of the book page.
So nothing is lost when the book is held open.
That said go ahead and give the gutter a 1 margin so the content of your book doesn t get lost in the fold.
Each of those margins has a particular job.
You write here about making the gutter margin wider as it slopes in but on 9 mar 2010 book page layout for a long narrative you wrote you want to keep the inside margin the one in the gutter or at the binding smaller than the outside because when the book is held open this will essentially double in size combining the inside margins of both pages in a space in the middle of the book.