Why not 1em for standard text?

[patrik]

Bought a new book today, and as it seems books from this author the size for standard text is "never" 1em. It's 0.933em (another book from him has 0.93em).

(He also uses larger right/left margins than most.)

Is this a cause of using something like Indesign or some other tool? Or is there an actual good reason for not having 1em? (For normal fiction, not poetry etc.)

Curiosity killed the cat..

[HarryT]

1em is the line spacing, isn't it? One might, therefore, expect the actual text to be a little smaller so there's a small gap between lines.

[patrik]

As far as I can tell, typical line spacing is 1.2em.

[pdurrant]

Originally Posted by patrik

Bought a new book today, and as it seems books from this author the size for standard text is "never" 1em. It's 0.933em (another book from him has 0.93em).

(He also uses larger right/left margins than most.)

Is this a cause of using something like Indesign or some other tool? Or is there an actual good reason for not having 1em? (For normal fiction, not poetry etc.)

Curiosity killed the cat..

There's no good reason for the body copy of an ebook to be anything other than the default size.

[DNSB]

Originally Posted by patrik

As far as I can tell, typical line spacing is 1.2em.

Line spacing should normally specified without any units. That way, it's applied to the current font size ( 1.2 x 1em, 1.2 x2em, etc.). This helps to avoid line spacing that is less that the font size. One horrible example is where the title elements are set in 2.5em with an inherited 1.2em line spacing.

As for the fractional font sizes, I've see that a lot and never saw a good reason for it. One author my wife reads loves using about 20mm left and right margins -- just like in the good old days when deadtree books were the only game in town.

[DNSB]

Originally Posted by HarryT

1em is the line spacing, isn't it? One might, therefore, expect the actual text to be a little smaller so there's a small gap between lines.

Depends whether your CSS is specifying font size or line height. My preference is 1em font size and 1.2 line height. YMMV.

    font-size : 1em;
    line-height : 1.2;

[GeoffR]

Originally Posted by patrik

Bought a new book today, and as it seems books from this author the size for standard text is "never" 1em. It's 0.933em (another book from him has 0.93em).

(He also uses larger right/left margins than most.)

Is this a cause of using something like Indesign or some other tool? Or is there an actual good reason for not having 1em? (For normal fiction, not poetry etc.)

Most likely just an artifact of the software used to create or convert the ebook, Maybe the original document had the font size for normal paragraphs set to 14pt, but the conversion software for some reason chose 15pt as the base font size to scale to, and so calculated the ebook font size for normal paragraphs as 14/15 = 0.933em.

However it could also be deliberate. Maybe the author tested the ebook on a reader that had a limited number of font size adjustment steps (some readers have a mere seven choices of font size!) and when they couldn't get the book to match their personal reading preferences by adjusting the font size from the reader they changed the size in the book instead. Same for the oversize margins, they probably look good when testing on a wide-screen PC.

[patrik]

Sounds plausible. Thank you GeoffR.

[DaleDe]

Originally Posted by pdurrant

There's no good reason for the body copy of an ebook to be anything other than the default size.

Don't forget pdurrants comment. Unless the book is only for yourself or it is a fixed size format, you should never set the default size for a book. This should always be left to user preference.

[patrik]

Yes, makes sense.

Hmm, I may send the publisher (or author) a mail and see what they say about this.

Thanks

[DNSB]

Originally Posted by pdurrant

There's no good reason for the body copy of an ebook to be anything other than the default size.

I haven't found a ereader or app that does not use the specified size as the starting size which can be modified by the user. Line height if set in the CSS, OTOH, does seem to disable the user's ability to change line height in most cases.

As for the default font size? As far as I can tell, that is a whole other can of worms. Testing multiple ereaders, apps and web browsers gave me a rather varied selection of font heights on screen when a default font size was not specified -- this was done using a test document when the body size was defaulted to 1em and the same test document with the font-size declaration removed.

[pdurrant]

Originally Posted by DNSB

As for the default font size? As far as I can tell, that is a whole other can of worms. Testing multiple ereaders, apps and web browsers gave me a rather varied selection of font heights on screen when a default font size was not specified -- this was done using a test document when the body size was defaulted to 1em and the same test document with the font-size declaration removed.

The question isn't whether the same document looks the same on lots of different devices - that will, of course, depend on the various devices' settings.

What should be avoided is having to change the settings on a single device for every new book to get the same apparent font size. And the way to do that is for books not to set the body font size, but leave it to the device defaults.

[HarryT]

Originally Posted by pdurrant

What should be avoided is having to change the settings on a single device for every new book to get the same apparent font size. And the way to do that is for books not to set the body font size, but leave it to the device defaults.

An entirely valid point, although at least specifying a body font size in "ems" doesn't prevent the size being changed, which specifying it in "absolute" units such as points, does.

[j.p.s]

Originally Posted by pdurrant

There's no good reason for the body copy of an ebook to be anything other than the default size.

It seems difficult to get across how important this is.

Originally Posted by DaleDe

Don't forget pdurrants comment. Unless the book is only for yourself or it is a fixed size format, you should never set the default size for a book. This should always be left to user preference.

Apparently this can not be repeated often enough.

Originally Posted by DNSB

As for the default font size? As far as I can tell, that is a whole other can of worms. Testing multiple ereaders, apps and web browsers gave me a rather varied selection of font heights on screen when a default font size was not specified -- this was done using a test document when the body size was defaulted to 1em and the same test document with the font-size declaration removed.

What matters is how the user has modified from the device default. The entirely reasonable expectation is to almost never have to change the default size when changing between documents.

Originally Posted by pdurrant

The question isn't whether the same document looks the same on lots of different devices - that will, of course, depend on the various devices' settings.

What should be avoided is having to change the settings on a single device for every new book to get the same apparent font size. And the way to do that is for books not to set the body font size, but leave it to the device defaults.

Amen.

Originally Posted by HarryT

An entirely valid point, although at least specifying a body font size in "ems" doesn't prevent the size being changed, which specifying it in "absolute" units such as points, does.

Just because the user can override the change is no reason to make a change to the body text size.

[Sarmat89]

Large books are usually set in smaller type, as it makes it easier to page through them.