Specs to format an epub for kobo

[verydeepwater]

Are there any specific specs to format an epub so that it is suitable for kobo? Or can you just use the same epub file for both?

[JSWolf]

Originally Posted by verydeepwater

Are there any specific specs to format an epub so that it is suitable for kobo? Or can you just use the same epub file for both?

For both what? The same ePub file that works on a Sony or B&N or Bookeen or others should work on a Kobo except maybe the embedded fonts because Kobo refuses to fix the embedded font bug.

[davidfor]

I have no problem using epubs obtained from other sites on either of my Kobo devices. Kobo do have their own format which is an epub with some extra tags. But I am fairly sure they just run a conversion of the standard epub to achieve that.

@JSWolf: You have mentioned the embedded font bug before, but I can't think of a discussion of it here. Can you point to one?

[JSWolf]

All Kobo's ignore font-family when they are included in the body CSS style. Some ePub that have embedded fonts turn them on via font-family in the body CSS style.

To me, this is a major bug. The only way to fix things so they work is to put the font-family in other CSS styles. I'm wondering though if a styled div could work like so...

<div class="font">
the chapter goes here
</div>

.font {
font-family: charis
}

[davidfor]

Ok, I can see what you are saying. If the book has the font family set for the body, it is ignored. As I have seen other fonts used in books on the device, styles for other tags probably work. It almost sounds like a deliberate decision to ignore the font on the body. Kobo does let the user choose the font to use and has a "Document Default" option. I would expect that this respected the document styling but choosing could let the user override this. I might have a play.

[jackie_w]

@JSWolf,

I have seen you refer to this Kobo 'bug' in various threads, but I have to confess that I don't know what you mean.

If I load a typical retail epub, containing an embedded serif font for the main body text, then I can see the publisher's font if I select 'Document Default' in the Kobo's select-a-font menu. This works even if the publisher has put the font-family declaration in body {...}.

Alternatively, if I prefer to use a Kobo internal font, or my own sideloaded font, for main body text then, again, I just select the one I want from the font menu.

Whichever of the above I choose, any extra special fonts embedded by the publisher to highlight selected passages of text also display correctly.

In what practical way is there a bug?

In real life, I've no idea why any Kobo owner would ever need to embed a main body text font as it's a lot less effort and disk space (not to mention more flexible), to just use the font menu.

[roger64]

Originally Posted by jackie_w

.../...

In real life, I've no idea why any Kobo owner would ever need to embed a main body text font as it's a lot less effort and disk space (not to mention more flexible), to just use the font menu.

Real life is pretty large. You may wish to embed fonts for many reasons: contents or aesthetics among them. For example, to display Greek quotes, true smallcaps, dropcaps using special Swash fonts for laser effects , etc.

For the time being Kobo ignore these special needs. You'll find here an example with any of these books:
https://www.mobileread.com/forums/sho...92#post2446592
- the EPUBs are not displayed correctly because Kobo ignores the Linux Libertine Display font (used for some titles and dropcaps) and the smallcaps font.

On the other hand, the six inch PDF with exactly the same display is perfectly displayed with the Kobo Glo.

And you may as well forget the endnotes, because the KoboGlo does not seem to know how to deal with them. After some tries, I've stopped playing hit and miss...

[jackie_w]

Originally Posted by roger64

Real life is pretty large. You may wish to embed fonts for many reasons: contents or aesthetics among them. For example, to display Greek quotes, true smallcaps, dropcaps using special Swash fonts for laser effects , etc.

Please don't misquote me. What I actually said was

In real life, I've no idea why any Kobo owner would ever need to embed a main body text font

In case the emphasised part is ambiguous, by main body text font I mean the font which will be used to display the epub's standard, plain paragraphs. I certainly didn't intend to imply that no Kobo owner would ever want to embed fonts to enhance certain portions of an epub, e.g. SmallCaps and DropCaps.

Originally Posted by roger64

For the time being Kobo ignore these special needs. You'll find here an example with any of these books:
https://www.mobileread.com/forums/sho...92#post2446592
- the EPUBs are not displayed correctly because Kobo ignores the Linux Libertine Display font (used for some titles and dropcaps) and the smallcaps font.

I will look at your linked post later (my schoolgirl French is somewhat rusty so I'll have to rely on Google translate ), but in the meantime all I can say is that I can and do display special dropcap and SmallCaps fonts on my Kobo Glo. See attached pics.

The only Kobo-specific problem with fonts that I have encountered so far is the fact that there is no built-in monospace font. But this can be solved in the same way as SmallCaps/DropCaps, i.e. either by embedding one or by css-referencing a sideloaded one in the Kobo /fonts directory.

[roger64]

Sorry if you feel I misquoted you, it was not intentional. I may be wrong because my KoboGlo is only two days old, but I read on the support forum that any Kobo font you wish to add should include a regular, italic, bold and bolditalic font. This leaves aside stand alone fonts like Linux Libertine Display or smallcaps (semibolds somewhere?).

Nevertheless, I added Linux Libertine to my Kobo and the Linux Libertine Display as well (I named it Linux Libertine Display-Regular ???)

You sent a nice dropcap screenshot. Up to now, I did not manage to display properly the dropcaps for my books (except with the six inch PDF version of my book) with the Kobo Glo. If you find a solution to get a normal display of them, I'll be happy to try it.

There is not need to speak French for this. The CSS file is quite standard, and who cares about the story?

[jackie_w]

I tried the first book on your list on my Kobo Glo.

Good news: Your embedded fonts are not being ignored, so the css is fine.

Bad news: Unfortunately they don't all look good. The smallcaps and dropcaps are OK but a bit too lightweight (IMO only). However the main body text and headings look terrible, with long vertical streaks. I can only assume this is something to do with the particular webfont .ttf files you've embedded. I happen to have a version of Linux Libertine as one of my sideloaded fonts. If I select it from the font menu the main body text looks fine again, which just leaves the headings as problematic. The Kobo obviously doesn't like some of your ttf files. I tried the same epub on my Sony PRS350 which displays fine - no vertical streaks at all - it's still a bit lightweight IMO.

I have to conclude that the Kobo is more picky about fonts than some other readers but the standard @font-face methods for embedded fonts do work as expected.

When publishing epubs which may be read on many different devices, font-embedding is a tricky business, so the fewer the better. IMO it's better to let each user pick their preferred font for main body text. If you're only preparing them for yourself (as I am) you just have to do a bit of trial and error about which ones look good on your own readers.

FYI - If you're only creating epubs for yourself then this recent post of mine shows how to css-reference a sideloaded font in the Kobo /fonts directory without needing to embed it. It works for fw 2.1.5 but I'm not able to test it on any later versions. Feel free to PM me with any questions.

[roger64]

Hi jackie

Kobo "weakness" with embedded fonts

Thanks for trying and for providing a useful link. Your observations recoup exactly what I noted. Contrary to ADE or Sony (yours and my former PRS-505)the way Kobo display the embedded fonts of my EPUBs is not satisfactory.

You pointed the fact that my CSS code is fine. Using strictly (not one letter change) this same CSS code and the same embedded fonts, Prince produces a PDF which is displayed fine everywhere, including on the KoboGlo.

I must conclude from this, that the implementation of embedded fonts display for EPUBs on the KoboGlo is whimsy. Call it a bug, a weakness, whatever, I don't know, but there is something wrong. Like for the endnotes display, if this is an hit and miss thing (yes for this font, no for the other one), it's not acceptable and this behaviour should be corrected.

I already wrote two days ago to the Kobo support about this.

Using dropcaps on EPUBs

Using dropcaps is a tricky business indeed, at least as long as you wish to use a special font to display your dropcap (as I did).

As the dropcap must be finely adjusted to the body font, you have to take also into account the metrics of these two fonts in your CSS values because they form a couple. For a safe display, it means that it's advisable to embed both fonts. As the regular font of Linux Libertine is already 800k, of course, it's better to embed a subset, if not your EPUB will be bloated.

I cannot see any other way out of this except renouncing to display dropcaps.

[meeera]

Originally Posted by jackie_w

However the main body text and headings look terrible, with long vertical streaks. I can only assume this is something to do with the particular webfont .ttf files you've embedded.

I haven't examined the source, but just as a possible clue, I think this has happened with some mis-named fonts. Perhaps fixing the name might help?

[roger64]

Originally Posted by meeera

I haven't examined the source, but just as a possible clue, I think this has happened with some mis-named fonts. Perhaps fixing the name might help?

You may be on to something. I will build again the webfonts and make a new try.

If somebody knows how Kobo checks a font-family name... I know already that for sideloaded fonts, they apply a strict naming-convention, maybe they follow some special rules for embedded fonts too?

Could FontForge be of some service for this? I mean renaming cleanly the font-family name or at least checking its proper name.

[Jellby]

Originally Posted by roger64

I cannot see any other way out of this except renouncing to display dropcaps.

Well... you could renounce to have perfect typesetting, which you already have to do for a number of other reasons. I think basic dropcaps can work pretty well in most situations.

[jackie_w]

Originally Posted by roger64

For a safe display, it means that it's advisable to embed both fonts.

...whereas the conclusion I would draw is that, if you're preparing epubs for others, it's advisable to embed neither If you're preparing them for yourself it's not difficult to find an acceptable solution. I don't think I'd want to give up the advantages of epub to get a fixed font selection in PDF, especially on a Kobo which doesn't seem like a great PDF reading experience (but that's obviously all just personal opinion )

Originally Posted by roger64

I cannot see any other way out of this except renouncing to display dropcaps.

If you let the dropcap display in the same font as the main body text, by removing the font-family setting from the dropcap class, then you'll have a fighting chance of success. This is what I do for most modern fiction books I read. I only add the fancy initials for a few book series (such as the Wheel of Time fantasy in my original pic).