Thanks to Kovid and General Comments

[rcentros]

I don't know if this is the right sub-forum to post this. There's an amazing amount of information about Calibre on this forum and sub-forums. It's kind of overwhelming. Thanks to Kovid for Calibre and for all those who support it here. I'm just a user, not not a developer or eBook creator.

But recently I discovered that I could convert my Kindle books for reading on my old Sony Readers using Calibre (once the De-DRM plugin was downloaded and installed). I like the build quality of the Sonys, but not being able to adjust the margins, line spacing and using fonts that seem too light for my taste meant the Sonys didn't get much use. Then I discovered that I could embed (if that's the right word) the Constantia font, change spacing and margins. Suddenly my T1, T2 and older Sonys are popular.

The T1 I'm using for a specific purpose and have about 110 books that I converted for it. Of those, about 90 converted directly from .mobi, .AZW3 (or, a few) from .ePub without issue. I just embedded Constantia, changed my Minimum line height to 130%, and kept ligatures. Then the top, left and right margins to 10 point and the bottom to 2. For a majority of books this worked without issue, but for a few (mostly from the same publisher when they still used .mobi instead of .AZW3 they've now adopted) I couldn't get the font to change. For these I found that, if I went to Styling and checked "remove font family CSS property" that worked for all but two or three books. Those two (or three) books required that I first convert them to .AZW3 and then to .ePub – and then one was still stubborn until I did this a couple times.

Obviously I'm just stabbing in the dark here – but I achieved what I wanted. I am curious, however, why some books worked without removing the old CSS font information while others (the minority) required that I check the Fonts setting in Styling. And also, should I just automatically delete CSS font settings (I don't seem to lose anything) on all conversions to a specific font?

Sorry to ramble. Thanks to everyone, especially Kovid, for supporting (or publishing) Calibre. An amazing program.

[kovidgoyal]

You're welcome

Basically, CSS has a type of priority system (called a cascade). When you embed a font it sets the "base" font used by the book. But if the book specifies its own fonts with higher priority, then that will not work, in this case you have to tell calibre to remove the existing font defintions, to allow the new base definition to become highest priority. calibre does not do this by default, because it can cause some loss, think of books that use a different font for headings or handwriting or similar. If you dont care about that, then yes you can always tell calibre to delete font styling information.

[rcentros]

Originally Posted by kovidgoyal

You're welcome

Basically, CSS has a type of priority system (called a cascade). When you embed a font it sets the "base" font used by the book. But if the book specifies its own fonts with higher priority, then that will not work, in this case you have to tell calibre to remove the existing font defintions, to allow the new base definition to become highest priority. calibre does not do this by default, because it can cause some loss, think of books that use a different font for headings or handwriting or similar. If you dont care about that, then yes you can always tell calibre to delete font styling information.

Thanks – answered all my questions. I think I'll only remove existing font definitions when it's necessary. Seems like the safest course. (Although I would still have the original anyhow.)

[FizzyWater]

I always wondered what the "cascading" part of "cascading style sheets" meant...thanks for the explanation!