Answers.Body: <p>To extend on Tom's answer I have to disagree with how the media type is written for Truetype and I would also like to show how its written for Opentype.</p>
  <p>In the <code>.opf</code> file <code>&lt;manifest&gt;</code>:</p>
  <h2>Truetype fonts</h2>
  <pre><code>&lt;item id=&quot;Roboto_Regular&quot; href=&quot;fonts/Roboto_Regular.ttf&quot; media-type=&quot;application/x-font-ttf&quot; /&gt;
  </code></pre>
  <p>media type for Truetype is: <code>&quot;application/x-font-ttf&quot;</code>.</p>
  <h2>Opentype fonts</h2>
  <p><code>&lt;item id=&quot;Roboto_Regular&quot; href=&quot;fonts/Roboto_Regular.otf&quot; media-type=&quot;application/vnd.ms-opentype&quot; /&gt;</code></p>
  <p>media type for Opentype should be: <code>&quot;application/vnd.ms-opentype&quot;</code> but I have seen <code>&quot;application/x-font-opentype&quot;</code> used and pass validation.</p>
  <p>Prior versions of Epubcheck I want to say used to check for this but I haven't tested it within <code>EpubCheck-3.0.1</code></p>
  <p>Be careful on how you code your paths when declaring the <code>src:url</code> in the <code>.css</code> file for the font.  I have seen some people use absolute paths when they should have used a relative path and it throw a validation error of an unused font.</p>
  <p>Note you cannot just include a master <code>.css</code> file that calls for a ton of fonts.  If you code for a font to be used in the <code>.css</code> file and include it in the package it must be used and declared in the <code>.opf</code> file or you will throw a:</p>
  <pre><code>&lt;Error&gt;
  &lt;Message&gt;'fonts/foobar.ttf': referenced resource missing in the package.&lt;/Message&gt;
  &lt;Line&gt;2&lt;/Line&gt;
  &lt;Column&gt;71&lt;/Column&gt;
  &lt;Resource&gt;foobar.css&lt;/Resource&gt;
  &lt;Class&gt;com.adobe.common.ReportElement&lt;/Class&gt;
  &lt;/Error&gt;
  </code></pre>
  <p>If you are not going to use the font you should remove it from the package and comment it out in the <code>.css</code> file</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-03-05T18:12:58.090Z
Answers.Text: Thanks for the expansion on my answer. I wouldn't have thought to try including a master font list in each CSS file, so I didn't know it would error like that. For the mimetype for truetype, I've been using that declaration for at least 3 years, and haven't had it return invalid or cause any problems in any reading systems. Do you have a reference for why `application/x-font-ttf` is better?
Answers.UserDisplayName: Tom
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-03-05T18:22:30.330Z
Answers.Text: From experience beyond iBooks I have found past issues with other platforms, devices and validation tools if it is not written with `media-type="application/x-font-ttf"`.
Answers.UserDisplayName: DᴀʀᴛʜVᴀᴅᴇʀ
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-03-05T18:27:23.793Z
Answers.Text: Interesting, thanks. I'll keep my eyes open for any errors that come back from any of the other retailers we deal with.
Answers.UserDisplayName: Tom
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-03-05T15:52:21.393Z
Answers.LastActivityDate: 2014-03-05T16:00:47.660Z
Answers.LastEditDate: 2020-06-18T08:36:04.683Z
Answers.UserDisplayName: DᴀʀᴛʜVᴀᴅᴇʀ
Answers.Body: <p>It is certainly possible to embed custom fonts and have them be used in iBooks, as well as on other <code>EPUB</code> reading systems. The process is known as embedding. Embedded fonts are simply included in the <code>.zip</code> archive that comprises the <code>EPUB</code> file, and then referenced properly in all the relevant content files. Places you will need to reference them include:</p>
  
  <h2>CSS file</h2>
  
  <p>This is just like using fonts on the web: the first thing you need to do is define <code>@font-face</code>:</p>
  
  <pre><code>@font-face {
    font-family: roboto;
    src: url('fonts/Roboto/Roboto-Regular.ttf')
  }
  </code></pre>
  
  <p>and then use that declaration in for whichever styles you'd like to use that font:</p>
  
  <pre><code>p.intro {
    font-family: roboto;
    font-weight: normal;
    font-style: normal;
  }
  </code></pre>
  
  <h2>content.opf file</h2>
  
  <p>Just like all the other files in your <code>EPUB</code>, you'll need to include any font files you're embedding in the <code>&lt;manifest&gt;</code> of your <code>.opf</code> file:</p>
  
  <pre><code>&lt;item id="Roboto-Regular_ttf" href="fonts/Roboto-Regular.ttf" media-type="application/x-font-truetype" /&gt;
  </code></pre>
  
  <p>The above steps are sufficient for most reading systems, but iBooks has one more hoop to jump through:</p>
  
  <h2>com.apple.ibooks.display-options.xml</h2>
  
  <p>This is a file that goes in the <code>META-INF</code> folder of the <code>EPUB</code>, rather than the OEBPS folder, and as the name suggests it's iBooks-specific. Neither this file nor the <code>container.xml</code> file need to be declared in the <code>&lt;manifest&gt;</code>, so don't worry about that. Here is the file in its entirety:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8" standalone="yes"?&gt;
  &lt;display_options&gt;
  &lt;platform name="*"&gt;
  &lt;option name="specified-fonts"&gt;true&lt;/option&gt;
  &lt;/platform&gt;
  &lt;/display_options&gt;
  </code></pre>
  
  <p>A more <a href="http://www.pigsgourdsandwikis.com/2011/04/embedding-fonts-in-epub-ipad-iphone-and.html" rel="nofollow noreferrer">in-depth writeup</a> can be found on Liz Castro's excellent blog. <a href="https://ebooks.stackexchange.com/a/866/349">As noted elsewhere</a>, be aware that there are some potential hurdles, both legal and practical, to embedding fonts.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-03-04T17:58:30.613Z
Answers.LastActivityDate: 2014-03-05T16:35:19.913Z
Answers.LastEditDate: 2017-04-13T13:00:05.480Z
Answers.UserDisplayName: Tom
Body: <p>Is it possible to include custom fonts in an ebook and have them show up in iBooks, or can you only use the various default fonts listed on the device?</p>
  
Tags: <epub><creation><fonts><production><apple-books>
Title: Can I make custom fonts show up in iBooks?
UserDisplayName: Tom
ThreadText: # Can I make custom fonts show up in iBooks?
  
  (Asked by: username_0 on 2014-03-04)
  
  Is it possible to include custom fonts in an ebook and have them show up in iBooks, or can you only use the various default fonts listed on the device?
  
  **Tags:** epub, creation, fonts, production, apple-books
  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_0 on 2014-03-04. Score: 7 | Accepted answer
  
  It is certainly possible to embed custom fonts and have them be used in iBooks, as well as on other EPUB reading systems. The process is known as embedding. Embedded fonts are simply included in the .zip archive that comprises the EPUB file, and then referenced properly in all the relevant content files. Places you will need to reference them include:
  CSS file
  This is just like using fonts on the web: the first thing you need to do is define @font-face:
  @font-face {
    font-family: roboto;
    src: url('fonts/Roboto/Roboto-Regular.ttf')
  }
  
  and then use that declaration in for whichever styles you'd like to use that font:
  p.intro {
    font-family: roboto;
    font-weight: normal;
    font-style: normal;
  }
  
  content.opf file
  Just like all the other files in your EPUB, you'll need to include any font files you're embedding in the  of your .opf file:
  
  
  The above steps are sufficient for most reading systems, but iBooks has one more hoop to jump through:
  com.apple.ibooks.display-options.xml
  This is a file that goes in the META-INF folder of the EPUB, rather than the OEBPS folder, and as the name suggests it's iBooks-specific. Neither this file nor the container.xml file need to be declared in the , so don't worry about that. Here is the file in its entirety:
  
  
  
  true
  
  
  
  A more in-depth writeup can be found on Liz Castro's excellent blog. As noted elsewhere, be aware that there are some potential hurdles, both legal and practical, to embedding fonts.
  
  
  ---
  
  ### Answer by username_1 on 2014-03-05. Score: 3
  
  To extend on username_0's answer I have to disagree with how the media type is written for Truetype and I would also like to show how its written for Opentype.
  In the .opf file :
  Truetype fonts
  
  
  media type for Truetype is: "application/x-font-ttf".
  Opentype fonts
  
  media type for Opentype should be: "application/vnd.ms-opentype" but I have seen "application/x-font-opentype" used and pass validation.
  Prior versions of Epubcheck I want to say used to check for this but I haven't tested it within EpubCheck-3.0.1
  Be careful on how you code your paths when declaring the src:url in the .css file for the font.  I have seen some people use absolute paths when they should have used a relative path and it throw a validation error of an unused font.
  Note you cannot just include a master .css file that calls for a ton of fonts.  If you code for a font to be used in the .css file and include it in the package it must be used and declared in the .opf file or you will throw a:
  
  'fonts/foobar.ttf': referenced resource missing in the package.
  2
  71
  foobar.css
  com.adobe.common.ReportElement
  
  
  If you are not going to use the font you should remove it from the package and comment it out in the .css file
  
  > **Comments:**
  > **username_0**: Thanks for the expansion on my answer. I wouldn't have thought to try including a master font list in each CSS file, so I didn't know it would error like that. For the mimetype for truetype, I've been using that declaration for at least 3 years, and haven't had it return invalid or cause any problems in any reading systems. Do you have a reference for why `application/x-font-ttf` is better?  
  > **username_1**: From experience beyond iBooks I have found past issues with other platforms, devices and validation tools if it is not written with `media-type="application/x-font-ttf"`.  
  > **username_0**: Interesting, thanks. I'll keep my eyes open for any errors that come back from any of the other retailers we deal with.  
  
  ---
  
  