What is the Mobipocket file formatHow do I create a Mobipocket eBookStandard eBooksAdvanced eBooks
Cross-platform feature supportImage supportTable supportCover PageParagraph rendering and hyphenationHyperlinksGuide itemsFramesIndexes and DictionariesSectionsAuthoring tips
Extended eBook features
Drug interaction module
a) General guidelines - read first
b) Cover Image
c) Table of contents
a) General guidelines
Writing HTML for a website and for an eBook is something quite different. There are many things people who design web pages tend to do which should be avoided for eBooks. The main reason is that eBooks are designed to be read both on desktops and mobile platforms with a very small screen. There are therefore some rules to follow to have an eBook that will render nicely on all types of screen.
- Do not impose the font family for the text. Most devices won't have your font anyway because a vast majority of mobile devices only have a couple of fonts. It is also better to let the user choose a font in the settings. Different fonts appear differently on different devices and users may prefer to use a sans serif font on a small screen but a serif font on bigger screens for instance.
- Do not impose the font size for regular text. Let the user choose the font size that gives him the best reading experience. It is of course ok to force bigger font sizes for headings, etc. Regular text should also not be bold or italic.
- Do not impose the justification (left aligned or justified) for regular text, let the user choose it in the settings. Justification looks very different on different devices because of the width of the screen.
- Do not impose the font color for regular text. Some people like to reverse colors (white text on a black background) for better reading comfort.
- Do not put blank lines of text to create empty pages for instance. Use the page break tag
<mbp:pagebreak/>. This is especially true for documents imported from Microsoft Word; you should use the "Page break" feature of Word.
- Do not create several versions of the book to try to support different screen resolutions (for instance one version for desktops and one version for mobile devices). The Mobipocket format and the Mobipocket Reader have features to achive an optimall
rendering of eBooks on all screens. For instance, font sizes are chosen optimally on each platform. If need be, you can use some advanced features of the file format like the multi-resolution images or platform dependent frames.
b) Cover image
- Your eBook should always have a cover image (which you can add by using the
"Cover Image" feature of the Mobipocket Creator). The preferred format for
the cover is a JPEG image of at least 600 by 800 pixels (825x1200 recommended).
- You can read more about cover image support in IDPF 1.0 and IFPF 2.0 standards in
the Cover Page article.
c) Table of contents, Index
It is generally a good idea to place a table of contents at the begining of the book so that users can easily jump to given locations in the book (typically to a given chapter). Here are a few guidelines for the table of contents:
- The TOC should be links so that users can click to jump to the location. A table of contents that is not made of links is useless.
- The TOC must be referenced from a guide item. This will make sure that the user
can access it easily from anywhere in the book.
Here is how to add a guide item in Creator.
- Do not leave the page numbers in the TOC. Page numbers do not make sense for an eBook because the text is reflowed. Click here for an explanation of the concept of reflowable layout.
- If you are importing your document from Word, you should use the "Index" feature of Microsoft Word. This will work only if you use the "Heading 1", "Heading 2",... styles. The index created by Word will be imported correctly and will convert to a TOC that follows the above guidelines.
- Indices that usually appear at the end of a book need to be completely reworked. You should not leave a plain text index with page numbers, as it will be of no value to the user. Please read the Scientific content / collection of articles section of this document to learn how to use the advanced indexing features.
- Mobipocket Reader supports the GIF, BMP and JPEG formats natively. You can also use PNG pictures in your content, they will be converted automatically during the build process.
- Mobipocket Reader does not support vector graphics. You will have to convert your vector graphics into raster graphics (for instance GIF or JPEG).
- If you are using pictures for schemas, charts, tables, maps or anything that has text, make sure that the text is still legible.
- Please refer to the Image Support article for more image quality guidelines.
Table tags have to be used only when displaying tabular data and not like in Web
page authoring for layout purposes. There is no exception to this rule.
- Nested tables are not supported: you cannot use a table tag inside
a cell of another table. However, rowspan and colspan attributes are supported.
- Avoid tables with lots of text in a single cell. If a single cell does not fit into
the screen, it will not be paginated and content will be lost.
- If you are thinking about rendering a table as a picture, please read the image
- Please read the Table support article, especially if you have large tables in your content
and want to make them work in your ebook.
UNICODE is supported in the Mobipocket file format, however, using rare characters
is not recommended because there is little chance that the reading device used by
your customer will have a font that supports the rare character.
At the end of every compilation in KindleGen or Creator, Unicode character usage is displayed. If your book uses unusual characters (outside of the Latin-1 or Windows-1252 range) there are two cases:
- If the characters can easily be replaced by standard characters then replace them (ex: long dash by standard dash). You will avoid the case when the user does not have the character in his selected font.
- If the characters are used for valid reasons, keep them (ex: Greek characters).
- (In some rare cases, words using exotic characters can be rendered as images. Phonetics
in dictionaries are a good example. In this case, be careful not to mix image characters
with normal text, it looks awful. It is recommended to use
multi-resolution images for words or characters rendered as images so as
to make sure they look reasonnably well on all devices. )
Most guidelines are summarized in this checklist. Before you add an eBook in eBookBase, you should test your book thoroughly. To do this, build your eBook using the "No encryption" option and open it in the Mobipocket Reader Desktop. Then check each one of the following points
- Open the book for the first time or go to the cover page
- Cover: eBook should have a cover, it will open directly on the cover if is has one
- Turn one or more pages
- Table of contents: if there is a table of contents, items in it should be clickable and jump to the correct location in the book.
- Go to any location in the middle of the book
- Font family: try to change the font family, the text of the book should appear immediately changed. If changing the font family does not change the appearance, it means the font is imposed; this should be fixed. In most cases all fonts should work. If not, it means you are using special characters in the content (like asian characters or special types of spaces or dashes).
- Font size: the size of regular text (not headings for instance) should be the pixel size in the settings. Regular text should not be bold or italic.
- Justification: Try to change the "full justication" layout setting. The text should appear differently. If not, it means the justification is imposed, this should be fixed.
- Colors: Try to change the font color and background color. If the font color does not change, it means that that it is imposed, this should be fixed.
- Go back to the first page, then flip through every single page of the book
- Pictures: they should not be too small. Make sure that all the text that appears in pictures is legible. Large pictures are scaled to fit in the page. Click on them to zoom in and scroll on them.
- Tables: tables should appear correctly. If some tables are completely broken, it means that nested tables were used; remove all tables used for layout.
- Page numbers: there should not be any reference to page numbers in the book. The table of contents should not have page numbers, cross references should not have page numbers, there should not be any plain text index with page numbers.
This sample illustrates the general guidelines. A majority of the text is left unformatted. It has a table of contents, a cover and a few pictures. Feel free to build and modify this book for testing purposes.