Lines split in half in e-book reader

[abecedarian]

After editing epub books in Sigil I usually read them in Calibre on my computer. Some books will show at the bottom of the page only the upper part of the line with the bottom part cut off, while the bottom part of the same line will be shown on the top of the next page with the top part cut off. I would very much like to know if there is a method to avoid such awkward behavior from happening. I've tried a few tricks, like adding margins to the css @page rule or to the body section, but to no avail. The funny thing is that the vast majority of epubs never show this problem, while some do and when they do they usually show them in copious amounts. I've added two sample images to clarify the problem. It's a nuisance that has irked me for years. I hope there is a solution. Thank you.

[jhowell]

Someone posted what appears to be the same problem in this thread. It is not clear what is going on. There is a possibility that it is font related.

[DNSB]

If it's any help, I notice that effect with the calibre viewer in flow mode but not in paged mode. I noticed it more with epubs using embedded fonts for the body fonts.

[abecedarian]

Thank you! Both of your answers are helpful.

The thread mentioned in jhowell's post gives as solution to switch to paged mode in Calibre. However, this seems more like a workaround solution to me. I definitely prefer to read my books in flow mode. As this solution is proposed by Kovid Goyal, the developer of Calibre himself, I suppose there's not much else that can be done about it. Nonetheless, I still wonder why only a small number of epub books show this partial lines problem in flow mode. The vast majority never exhibit this problem in flow mode, so I guess there must be something in the problematic epub files that provokes the problem which distinguishes them from the problem-free epubs.

As to DNSB's suggestion that it might be related to embedding fonts. I generally embed several of my favorite fonts in the epub files in order to make the reading experience more pleasing, and still hardly any epub books show this problem. So I don't think it might be related to the fonts that are used in the book.

[Quoth]

Books are paged, for over 2000 years. Scrolls and unfortunately websites are one long thing, less useful.

I'd like a web browser plugin to paginate to the current window size.

I've seen Firefox to this to some web pages that are printed.

[Hitch]

Originally Posted by abecedarian

Thank you! Both of your answers are helpful.

The thread mentioned in jhowell's post gives as solution to switch to paged mode in Calibre. However, this seems more like a workaround solution to me. I definitely prefer to read my books in flow mode. As this solution is proposed by Kovid Goyal, the developer of Calibre himself, I suppose there's not much else that can be done about it. Nonetheless, I still wonder why only a small number of epub books show this partial lines problem in flow mode. The vast majority never exhibit this problem in flow mode, so I guess there must be something in the problematic epub files that provokes the problem which distinguishes them from the problem-free epubs.

As to DNSB's suggestion that it might be related to embedding fonts. I generally embed several of my favorite fonts in the epub files in order to make the reading experience more pleasing, and still hardly any epub books show this problem. So I don't think it might be related to the fonts that are used in the book.

What happens if you don't use embedded fonts? What happens if you remove all embedded fonts and use a default font? That would be my very first troubleshooting step, so...can you tell us?

Hitch

[abecedarian]

Hi Hitch,

Thanks for giving a helping hand. After removing all embedded fonts plus all the font references in the css and html files there are no more split lines in the problematic ebook. Which admittedly means that my impression that the problem is not font-related may be wrong. Then again, the vast majority of epub books on my computer embedding the same fonts as there are in the problematic epub books does not show this problem. It is something that I notice fairly rarely, but it remains an annoying issue when that happens.

[Hitch]

Originally Posted by abecedarian

Hi Hitch,

Thanks for giving a helping hand. After removing all embedded fonts plus all the font references in the css and html files there are no more split lines in the problematic ebook. Which admittedly means that my impression that the problem is not font-related may be wrong. Then again, the vast majority of epub books on my computer embedding the same fonts as there are in the problematic epub books does not show this problem. It is something that I notice fairly rarely, but it remains an annoying issue when that happens.

Yes, but you're assuming that it's the font itself. Why can't it be the "how" of how the font is embedded, that's wreaking the havoc?

Hitch

[abecedarian]

No, I'm not assuming that it's the font itself, I just said that it might be font-related, that somehow it has something to do with the font. Still I have to say that I don't quite understand what you mean by how the font is embedded. What I do when I embed a font is I upload the fonts to the Fonts folder in the book and then I declare them in the css file. I always thought that's the only way to do it correctly, but I'm very much open to learning how to do it differently if that will get rid of the annoying split lines issue.

The way I declare the font in the css file is like this:

@font-face {
font-family: "Charis SIL";
src: url(../Fonts/CharisSILR.ttf);
font-style: normal;
font-weight: normal;
}

EPUB-Check gives the following comment:

INFO CSS-007 /OEBPS/Styles/stylesheet.css
(line 3, col 5) Font-face reference OEBPS/Fonts/CharisSILR.ttf refers to non-standard font type application/x-font-ttf.

EPUB-Check does not mark this as an error, but plainly there seems to be something unusual about this specific font declaration. Nonetheless, in other books this font and declaration only rarely lead to problems like this thread's issue.

I hope this helps to clear up the matter a little bit.

[Hitch]

Originally Posted by abecedarian

No, I'm not assuming that it's the font itself, I just said that it might be font-related, that somehow it has something to do with the font. Still I have to say that I don't quite understand what you mean by how the font is embedded. What I do when I embed a font is I upload the fonts to the Fonts folder in the book and then I declare them in the css file. I always thought that's the only way to do it correctly, but I'm very much open to learning how to do it differently if that will get rid of the annoying split lines issue.

The way I declare the font in the css file is like this:

@font-face {
font-family: "Charis SIL";
src: url(../Fonts/CharisSILR.ttf);
font-style: normal;
font-weight: normal;
}

EPUB-Check gives the following comment:

INFO CSS-007 /OEBPS/Styles/stylesheet.css
(line 3, col 5) Font-face reference OEBPS/Fonts/CharisSILR.ttf refers to non-standard font type application/x-font-ttf.

EPUB-Check does not mark this as an error, but plainly there seems to be something unusual about this specific font declaration. Nonetheless, in other books this font and declaration only rarely lead to problems like this thread's issue.

I hope this helps to clear up the matter a little bit.

I agree, as I mentioned earlier, that this is a bizarre one. Everything you've done, to me, looks okay.

I know that Wolfie, here on the forums, uses that Charis SIL all the time. I don't, so I don't know if there's something specific that needs to be addressed.

I have one suggestion and it's a dumb one, but...move the font URL declaration (src:url...) to the end of the @font-face declaration in the CSS sheet.

Try that and see if it helps. I know, I know, it's dumb as hell, but I've had stupider ideas that worked.

Hitch

[abecedarian]

I'm sorry to say that it didn't help. I hope I understood what you meant. What I did was I moved the line with the src:url part to the last line in the declaration, just before the closing curved bracket, the }. Like this:

@font-face {
font-family: "Charis SIL";
font-style: normal;
font-weight: normal;
src: url(../Fonts/CharisSIL-R.ttf);
}

The line at the bottom of the page still gets split into two halves.

[JSWolf]

Originally Posted by Hitch

I agree, as I mentioned earlier, that this is a bizarre one. Everything you've done, to me, looks okay.

I know that Wolfie, here on the forums, uses that Charis SIL all the time. I don't, so I don't know if there's something specific that needs to be addressed.

I have one suggestion and it's a dumb one, but...move the font URL declaration (src:url...) to the end of the @font-face declaration in the CSS sheet.

Try that and see if it helps. I know, I know, it's dumb as hell, but I've had stupider ideas that worked.

Hitch

There is nothing wrong with the code. The problem is that he's reading his ePub as KePub and if you've patched it, a bug appears that cuts off part of the top line of the next page if you don't have the line height wide enough. It's one reason I don't read KePub all that much.

The solution to the problem is to read ePub. Charis SIL can show the problem depending on which version(s) of Charis SIL is being used. If you do not need to zoom images, use footnotes, or have any ePub 3 features you need, then reading as ePub is better (IMHO).

[abecedarian]

Hi Jon, thanks for helping. I'm not sure I understand why you say that I'm reading the epub as kepub. I haven't converted or patched the epub to kepub, nor am I reading it on a Kobo e-reader. To my knowledge this is a regular epub file and I'm reading it on my computer using Calibre. How can I tell if the epub is a kepub in disguise?

[JSWolf]

Originally Posted by abecedarian

Hi Jon, thanks for helping. I'm not sure I understand why you say that I'm reading the epub as kepub. I haven't converted or patched the epub to kepub, nor am I reading it on a Kobo e-reader. To my knowledge this is a regular epub file and I'm reading it on my computer using Calibre. How can I tell if the epub is a kepub in disguise?

Because what you describe is a common thing to happen with a patched Kobo reading KePub using Charis SIL. Now if you are using Calibre 5.2, then report this in the Calibre Viewer forum. If not, install Calibre 5.2 and if you still have the problem, then report it.

[Hitch]

Originally Posted by JSWolf

Because what you describe is a common thing to happen with a patched Kobo reading KePub using Charis SIL. Now if you are using Calibre 5.2, then report this in the Calibre Viewer forum. If not, install Calibre 5.2 and if you still have the problem, then report it.

Jon, dear, he SAYS he's not reading it on a kobo. ???

Hitch