Help: missing embedded fonts after ePub3 transfer to Kindle

[Nightjar]

Dear friends,
After many years of happy ePub2 coding – whose files were converted to .mobi using Amazon's Kindle Previewer to provide the widest choice for our readers – we were forced to start from scratch and build a new ePub3 structure for our ebooks.

Everything is fine on any "basic" ePub reader (including ADE) and Apple Books, but when we sideload ePub3 files on our Kindle readers, all the custom fonts we use are completely missing.

Please note that if we convert the ePub3 files to .mobi using Kindle Previewer 3.70 and copy them to the same readers, all the custom fonts show up. So, there seems to be something "filtering" these fonts.

We have tried everything and of course all the ePub3 and CSS validations passed with flying colours, but basically now we are stuck because we don't know how to get a Kindle reader to properly display an ePub3 with embedded fonts.

Any help or suggestion would be greatly appreciated!

Thanks.

[phillipgessert]

How are you creating the epubs? If vía InDesign, they’re likely getting obfuscated, and InDesign’s font obfuscation will not work for kindle. The method of sideloading you’re using also matters. If sideloading vía something like a send-to-kindle address, the book is treated as a personal document, losing a lot of styling in the process.

[JSWolf]

Originally Posted by Nightjar

Dear friends,
After many years of happy ePub2 coding – whose files were converted to .mobi using Amazon's Kindle Previewer to provide the widest choice for our readers – we were forced to start from scratch and build a new ePub3 structure for our ebooks.

Everything is fine on any "basic" ePub reader (including ADE) and Apple Books, but when we sideload ePub3 files on our Kindle readers, all the custom fonts we use are completely missing.

Please note that if we convert the ePub3 files to .mobi using Kindle Previewer 3.70 and copy them to the same readers, all the custom fonts show up. So, there seems to be something "filtering" these fonts.

We have tried everything and of course all the ePub3 and CSS validations passed with flying colours, but basically now we are stuck because we don't know how to get a Kindle reader to properly display an ePub3 with embedded fonts.

Any help or suggestion would be greatly appreciated!

Thanks.

Mobi does not handle embedded fonts. So that's not going to work. Create KF8 format eBooks. They do support embedded fonts.

But the problem with a Kindle is that they do not display embedded fonts by default. You have to go to the Aa menu and select Publisher Font. Many won't do that. So your best to not embed fonts and make your eBooks work with a Kindle using KF8 without embedded fonts.

[Nightjar]

Originally Posted by phillipgessert

How are you creating the epubs? If vía InDesign, they’re likely getting obfuscated, and InDesign’s font obfuscation will not work for kindle. The method of sideloading you’re using also matters. If sideloading vía something like a send-to-kindle address, the book is treated as a personal document, losing a lot of styling in the process.

We are coding our ebooks using Sigil, the custom fonts are open source .ttf files, and the only allowed method to make an ePub3 readable by Kindle readers is to send it through Send-to-kindle using either the standalone software or their new webpage (https://www.amazon.com/sendtokindle). Making a direct copy of an ePub3 file via USB in Kindle reader's document folder simply doesn't work, because the reader can't open those files.

[Nightjar]

Originally Posted by JSWolf

Mobi does not handle embedded fonts. So that's not going to work. Create KF8 format eBooks. They do support embedded fonts.

As already reported, when we export our ePub3 as a plain .mobi file using Kindle Previewer 3, the resulting file can be copied directly into the documents folder of a Kindle Reader, which loads and displays all our custom fonts beautifully.

It is true that the users can always choose to display the text with one of the default fonts instead, but after sideloading an ePub3 to a Kindle Reader there is no difference when switching from "Publisher font" to "Amazon Ember". This is clearly a problem with how the file was changed during the transfer or how the Kindle Reader recognizes the ePub3.

Hope to find a solution to this conundrum.

[phillipgessert]

Sounds like it’s the sideloading issue. You might see if directly loading an AZW file fares better, because send-to-kindle with an epub file sends it through the same (or similar) conversion process that something like a Word file gets.

[Quoth]

real plain mobi (KF7 and azw) NEVER has embedded fonts. That's only possible with azw3 (KF8), dual mobi (KF7 and KF8 in one overall file) and the KFX.

if you are distributing via Amazon KDP, (or using Send to Kindle) then upload checked epub2 also verified on real eink epub readers and on real Amazon Kindle eink via epub to azw3 conversion in Calibre. Older than KK3, DX and DXG only work with old mobi, KF7. A KK3 on older Firmware can't do azw3.
Amazon sends the user old mobi (maybe azw), azw3 or KFX depending on what it's being sent to.

[JSWolf]

Originally Posted by Nightjar

As already reported, when we export our ePub3 as a plain .mobi file using Kindle Previewer 3, the resulting file can be copied directly into the documents folder of a Kindle Reader, which loads and displays all our custom fonts beautifully.

It is true that the users can always choose to display the text with one of the default fonts instead, but after sideloading an ePub3 to a Kindle Reader there is no difference when switching from "Publisher font" to "Amazon Ember". This is clearly a problem with how the file was changed during the transfer or how the Kindle Reader recognizes the ePub3.

Hope to find a solution to this conundrum.

You are wrong. Mobi does not support embedded or side loaded fonts on a Kindle. What you are doing is creating a dual-format file that contains Mobi & KF8. The KF8 is what's displaying the embedded fonts. You are best to create a separate mobi and KF8 then a dual-format file. Most will look at it and think it's a Mobi.

Does your eBook work when the embedded fonts do not display? If so, dump the fonts as you have no way of getting them to work on an older Kindle.

[JSWolf]

Originally Posted by Quoth

real plain mobi (KF7 and azw)

Mobi has never been officially called KF7. Using that term for the format can be confusing because it's wrong.

[Nightjar]

Originally Posted by JSWolf

You are wrong. Mobi does not support embedded or side loaded fonts on a Kindle. What you are doing is creating a dual-format file that contains Mobi & KF8. The KF8 is what's displaying the embedded fonts. You are best to create a separate mobi and KF8 then a dual-format file. Most will look at it and think it's a Mobi.

Ok, I agree that Amazon made a mess out of the .mobi file specs, but when their main conversion software saves a file with .mobi extension, I call it "mobi", even if does contain KF8.

However, my problem is still standing: when we offer our readers the option to buy a .mobi (+embedded KF8) version, everything is fine, whereas now that Amazon has officially discontinued .mobi support, forcing us to switch to ePub3 instead, there seems to be no way to allow Kindle Readers – even the most recent Paperwhite versions – to display any "Publisher font" correctly. Which is puzzling.

[Doitsu]

Originally Posted by Nightjar

Everything is fine on any "basic" ePub reader (including ADE) and Apple Books, but when we sideload ePub3 files on our Kindle readers, all the custom fonts we use are completely missing.

1. When previewing your books with Kindle Previewer, are the embedded fonts correctly displayed and is the app showing the green Enhanced Typesetting check mark for your books?
   
2. How exactly did you sideload your ePub3 files and what apps and/or devices did you you test your sidedloaded books with?
3. Did you enable/select the Publisher Font option?

[Quoth]

Originally Posted by Nightjar

there seems to be no way to allow Kindle Readers – even the most recent Paperwhite versions – to display any "Publisher font" correctly. Which is puzzling.

Untrue. Convert epub2 to Dual mobi (or AZW3 only for direct USB)
Any Kindle with FW later than about 3.4.x has Publisher option on fonts or themes. Then embedded fonts are shown. The Dual mobi is pointless other than your own website or Smashwords for unknown Kindle models.

We've been doing it since about 2015 when the PW3 was released!

Amazon KDP uploaded with epub2 and embedded fonts works on anything Amazon delivers using azw3 or KFX. Really ancient Kindles get old mobi format. We test any new styles/formats of ebook in old mobi (Calibre epub2 to old mobi (KF7) on a DXG and KK3 to make sure the ebook still works using the limited old fonts (serif, sans & monospace with normal, bold, italic or italic bold). Wordprocessor styles need to include suitable font names especially to get monospace font (which while not on GUI list, is there).

BUT the only place in the world you send azw3 to is a local kindle via USB.

Smashwords redistributes uploaded epub2 to Kobo, Barnes&Noble, Apple etc and sells it direct.

The only place you upload dual mobi to is Smashwords for their own customer.

Use epub2 for Google, Smashwords and Amazon and that is about 100% distribution for English (as Smashwords/D2D redistribute to the significant others such as Kobo, Scribd, Tolino, Barnes&Noble and Apple).
If you really need epub3 features then it's probably not a regular ebook (and an app is better). The epub2 reaches everything.

[Nightjar]

Originally Posted by Doitsu

1. When previewing your books with Kindle Previewer, are the embedded fonts correctly displayed and is the app showing the green Enhanced Typesetting check mark for your books?
   
2. How exactly did you sideload your ePub3 files and what apps and/or devices did you you test your sidedloaded books with?
3. Did you enable/select the Publisher Font option?

1) Yes, using Kindle Previewer my custom fonts are being displayed correctly and the green "Enhanced Typesetting" is checked (see screenshot)
2) The only possible way to sideload the ePub3 file to a Kindle Reader is through their "Send-to-kindle" option, either using the desktop PC sowftare or their special webpage. I have tested it in:

• Kindle Paperwhite (2022)
• Kindle Fire HD 7"
• Kindle Touch (2012)

3) Yes, of course I have enabled the "Publisher Font" option

Kindle Previewer Screenshot displaying custom fonts:

[Quoth]

Originally Posted by Nightjar

2) The only possible way to sideload the ePub3 file to a Kindle Reader is through their "Send-to-kindle" option, either using the desktop PC sowftare or their special webpage. I have tested it in:

No, that's an inferior way.
The best way is Calibre conversion of epub2 to either azw3 or dual mobi. Though epub3 should work, but pointless.

If you are publishing then only upload of epub2 to KDP counts, and DON'T download the preview but buy retail copies for later or ancient kindlles, both by Download for PC for USB transfer (azw3 on most kindles) and Whispernet/WiFi for eink kindles and direct for Fire or Apps (both will give KFX, except on Apple iOS, except on ancient Kindles which will be mobi or azw (KF7)).

The Send to Kindle email or Web is a courtesy service for two reasons:
1) For people that don't know how to convert epub
2) So Amazon gets a copy. Analytics/Analysis of users.
It's totally inferior to conversion (without Amazon tools) and USB transfer.

Upload of epub to KDP is the only thing that counts for Amazon distribution.
Only the direct downloads to apps or later eink or Fire get KFX from Amazon which is the only thing with "Enhanced Typesetting" and works perfectly with epub2 upload.

You can also add a plugin to Calibre for KFX, to text or if you like KFX, but you can't upload old mobi, true dual mobi (from Calibre for Smashwords), AZW/KF8 or KFX to Amazon. You can upload docx, but epub2 works best. If people have old Kindles and you upload docx they don't get page breaks at all in the mobi file. If you upload epub2 that has a new HTML file for every page break (even if not a chapter), then that's where the page breaks are in EVERY downloaded Amazon format.

I decided years ago that Kindle Preview was a waste of time compared to real Kindles and for any new style/format (not new ebooks or edited ebooks using same WP styles) we buy a copy and do two kinds of download for USB transfer (old model and PW3 registered, and Oasis gen 2 made no difference) and direct WiFi on Paperwhite 3 without USB.

[JSWolf]

Originally Posted by Nightjar

Ok, I agree that Amazon made a mess out of the .mobi file specs, but when their main conversion software saves a file with .mobi extension, I call it "mobi", even if does contain KF8.

However, my problem is still standing: when we offer our readers the option to buy a .mobi (+embedded KF8) version, everything is fine, whereas now that Amazon has officially discontinued .mobi support, forcing us to switch to ePub3 instead, there seems to be no way to allow Kindle Readers – even the most recent Paperwhite versions – to display any "Publisher font" correctly. Which is puzzling.

The thing is, the Mobi you get is not a true Mobi. It is a dual format that contains Mobi and KF8. When you load this into a PW3, with this eBook displaying, go tot he Aa menu and select Publisher Font. If you see the embedded fonts, all is well with the KF8 format. But, you do need to see if your eBook works without these embedded fonts as the Mobi part of the file will not display the embedded fonts on a Kindle (1st gen), Kindle 2 (2nd gen), or a DX/DXG. And if you don't actually need these embedded fonts, don't bother with them.

After looking at your screen shot of Kindle Preview, it looks like you don't need the embedded fonts.

The best way to test your eBook on a Kindle is to get a copy of Kindlegen. Use Kindlegen to convert your ePub to the dual-mobi format. For the next steps, you will need to have Calibre installed with the KindleUnpack plugin installed. Load the dual-format Kindle eBook into the Calibre library and using KindleUnpack, split the dual-format eBook into the two parts (Mobi & KF8). Then load the separate format eBooks into Calibre and send them to your PW3. Now you can test both formats to see what you get.

But one thing to note, @Hitch (who is a professional eBook maker and who's word on this I trust) embedded fonts on Kindle eBooks for sale if you are not one of the big publishers is a pain in the ass and most of the time, the embedded fonts get stripped from the eBook.