Your book may have a smashing cover, but what about the interior text. Are there design questions here, too? You bet there are.
Page size: For economic reasons relating to the tim size of paper and printing presses, most books fall into the 5 3/16" x 8"1/4" to 6" x 9"size. Recently a range of 7" x 9" to 7" x 10" has also emerged. Think about the use for your book. If you want to include business letters or forms, 8 1/2" x 11" might be more practical. Gift books often run 6" x 4" or 6" x 4 1/2". However, if you choose to use an odd and unconventional trim size, be prepared to pay more and work closely with your printer.
A good suggestion is to visit your local bookstore and look at the trim sizes of books in your genre. This may provide you with an idea of what is acceptable.
Paper: While paper is certainly a design consideration, it also affects cover design because of the spine width, and can have great bearing on your overall printing costs. Depending on the number of pages and the quantity of books to be printed, paper costs can run from 28 to 50 percent of the total printing bill.
Paper is chosen for its weight, opaqueness and color. If you have a skinny book, use a "high bulk" paper, and the book will appear fatter. You'll pay more for the paper, but if it will make your book appear to be a better value and allows you to charge more for it, this stock may be a wise investment.
Most books (with the exception of photo books) use 50-, 55-,or 60-pound paper. Ask your printer for samples. Be aware, however, that a 60-pound paper from one printer may differ from a 60-pound paper from another.
Today virtually all papers are acid free. This means your book will till be in good shape a century from now.
So when it comes to designing your book, make sure you consider your interior pages as well as your cover. Elements such as trim size and the type of paper you choose will affect appearance, cost and ultimately saleability.
[This post was created, with permission, from excerpts taken from The Complete Guide to Self-Publishing, 5th edition, co-authored by Marilyn Ross and Sue Collier.]