The gutter, alley, and creep are all terms that are common in publishing or graphic design. The inside margins closest to the spine of a book or the empty space between two facing pages in the middle of a newsletter or magazine are known as the gutter. Gutter space includes all the extra space needed to bind books, booklets, pamphlets, brochures, newspapers, and magazines. The amount of gutter needed varies depending on the binding method.
Don't get lost in the book gutter | Children's book design | Book illustrations
When preparing digital files for print publication, a designer may need to adjust the gutter width. It all depends on the specifications of the printing company handling the production.
Gutter adjustments for three-ring pages or side-stapled booklets are a single measurement applied to each left and right page. The print shop may want you to include that measurement in your digital files.
In some cases, designers use the terms "gutter" and "alley" interchangeably, depending on the project. Both have distinct meanings. Both are strips of white space, the main difference being their size and location in relation to page layout. An alley is a space between columns of text on a single page, such as in a newspaper, used in page layout. The gutter is the white space between the two pages in the middle spine of the publication.
