Kaitlyn Thheoretically, Yes, .kes is preferable. From a practical standpoint, however, it is a recipe for having your submissions languish from being validated by a volunteer as that validator must have K1000 available to them. So, from a practical standpoint, the best format to choose is .rtf which almost all validators can easily handle. I scan using K1000 myself. When I am working on a book, I save it in .kes. Before submitting it to Bookshare, however, I convert it to .rtf using K1000's ""save as" feature on the file menu.