[FM Discuss] Booktype CSS

[Daniel James]

Hi Martin,

> If font size is defined at the start of the CSS document, with say, 
> 
>      html { font-size: 12pt; }
> 
> then all following measurement units could be in ems

I think that would appeal to designers with a book typography background.

Specifying font size in pixels might make sense to ebook designers, but
isn't very intuitive if you're aiming for PDF and print output. That's
because a pixel can be any size in real life, depending on the output
device, whereas a printer's point is (these days) always 1/72 of an inch.

Font size is more critical for printed books, where a slight increase
can increase your page count (and therefore costs). In the worst case
scenario, it screws up your pagination so that your page count goes just
over a multiple of eight (or whatever), meaning that you're paying the
printer for several blank pages at the end of the book.

Cheers!

Daniel