In the publishing phraseology, trim size defines the size of the book as the width and height dimensions of the book pages. The book layout and book design of the book is greatly affected by the book trim size. In both economic and aesthetic terms, how big a book is classified relies on the trim size that it is allocated.
Here are the following things to be aware of when choosing a book trim size:
Be knowledgeable about industry standards.
However, in trade paperbacks (fiction and nonfiction books that range from light novels to textbooks), the trim size varies across various genres. On the other hand, comic books and mass market paperback books follow a single industry-wide standard. When used alongside manuals, workbooks, and art books, manuals, workbooks, and art books each have unique and distinct standards. Have an idea of the standards that apply to your genre of writing.
Be mindful of your reader.
It's good to follow publishing genre conventions when working in well-established genres like horror, sci-fi, or romance. Since readers tend to gravitate to things they know, your book should at least appear familiar to your target readers.
Think about how your design looks.
Trim size is just one of the many things you'll need to consider when you're self-publishing a novel using a print-on-demand service. If you have decided to publish a story in trade paperback size, then say so. Choosing the trim size will determine the book's height and width and the number of pages. If the book's trim size is made larger, it won't look like an unappealing brick. Larger works will likely benefit from being given less of a haircut, which will help them appear more substantial.