Bleed is a printing term that is used to describe a document which has images or elements that touch the edge of the page, extending beyond the trim edge and leaving no white margin. When a document has bleed, it must be printed on a larger sheet of paper and then trimmed down.
If you are looking to have any images or background colors in your book run all the way to the edge of the page, your document must include bleed.
Bleed extends your full page images and background colors 1/8th of an inch beyond your trim measurement. When things are commercially printed, they are printed on a larger sheet, and trimmed down to size. If you try and trim along the line where the print meets the unprinted area, you end up with a “flash” of the unprinted white sheet. Including bleed removes this white flash from your finished trimmed sheet.
Bleed is accommodated in all of the BookBaby template files we have on our site, including the Word templates.
A quick, and easy, way to see if your files have bleed is to check the page size in your PDF. If the pages are .25” larger than the trim size then you have bleed. If the pages are exactly the trim size, they do not have bleed.
If your files do not contain any elements that are supposed to go to the edge of the trimmed page (text only books, or intended unprinted borders around any images), then it is not crucial for you to include bleed on the content of your book. You will just notice that your proof does not display properly.