What should the resolution be for images used on or in my book?

We suggest using a high resolution image of 300 DPI (dots per inch) or higher at the size you want it to appear in the book's interior pages or on the cover. Any image less than 300 DPI will not look as clear as it could, but it can still be included in your book as long as the resolution is no less than 150 DPI. Depending on the degree of quality, an image less than 300 DPI will look grainy or blocky when printed, instead of crisp and clear. Therefore, it's in your best interest to use high resolution images in your book in order to achieve a professional appearance.