One thing you will want to keep in mind when preparing files for the eBook on your custom flash drive is page size and orientation. If all your files are the same size and orientation, there is no issue. If your files contain multiple page sizes then you need to be aware of how our eBook publishing software will display these differences.
Page orientation is the way in which a rectangular page is oriented for normal viewing. See… https://en.wikipedia.org/wiki/Page_orientation.
Portrait Orientation is represented by a shorter width and a longer height. 8.5″ Wide x 11″ High
Landscape Orientation is represented by a wider width and a shorter height. 11″ Wide x 8.5″ High
Why Does This Matter
Keeping it simple… If there is no way to avoid the multiple page size issue, a book that is sized portrait, but contains landscape oriented files(or vice versa) will fill the remaining space with a solid color. Usually white, but it can be any color you prefer. See the following examples…