I learned a lot about Word while formatting my first self-published novel. One of those things involved paragraphs and how they look on the pages of a print novel. This is important so pages don’t look like they have a narrow column of text in the middle of the page; the margins around the text appear too large. Instead, the text nestles close to the book’s interior spine (gutter) evenly on the left and right pages. Adjusting the mirror margin allows that to happen. The margins of the left page are a mirror image of those on the right page.

So, how is this accomplished?

1. Select Layout from the top ribbon in Word.
2. Select Margins then Custom Margins. This will open a page set-up box.
3. There will be three tabs across the top: Margins, Paper, and Layout. Stay on the Margins tab. This tab has four sections under it: Margins, Pages, Orientation, and Preview. Under Pages there is a dropdown box beside the words Multiple Pages, select mirror margins from there.
4. This section will change the Preview section (below it) to show two pages instead of one. It will also change the selections from the Margin section (above it) so that it reads “inside” and “outside” instead of “left” and “right.”
5. You then adjust the numbers in the Margin section for top, bottom, inside, outside, and gutter. For print novels, leave the gutter position set to the left. I can’t be specific about how to adjust the spacing because several factors, like the book’s size, will affect the change. You might need to experiment with it before you get the best interior look for your book.
6. Ensure that under the Preview section Apply to is set to “whole document.”

Note One: Under the Paper tab, you need to set the paper size for a custom width and height. A paperback novel is typically 5 by 8.

Note Two: When you adjust the numbers for inside, outside, and gutter you can see what happens to the text under the preview section. The horizontal lines (which represent the text in the manuscript) will move left and right, shrinking or expanding the lines of text. When you adjust the gutter, a vertical checkered line appears on the inside margin of both pages. This line grows thicker as the number in the gutter box is increased.

Note Three: These are tips on formatting your manuscript and not an order in which to apply them. There are many formatting items for a manuscript. To name a few: use of a drop cap, paragraph indentation, orphan tasks, font choice, line spacing . . .

A Google search should bring up various other posts and videos regarding the creation of mirror margins.