Fonts and Typography in Digital Content

Unit Overview

The fonts and typography unit is a set of articles explaining the use of  font and typographical features now available in major digital content rendering engines and browsers. This information probably only applies to ePub3 (unless you are using AZARDI).

Articles specifically address:

• CSS-3 Font properties
• Font sub-setting and how to do it.
• Glyphs and Font-features

There are also two demonstration font character and glyph tables section available for the MEgalopolis Extra and Linux Libertine regular font-faces, exposing all.

Fonts and Typography in Reflowable Digital Content

With the newly unleashed power of the W3C CSS-3 fonts module, advanced typographic techniques are available in digital content, and in some respects improve significantly on print tools for access and usability.

CSS-3 font-weights, styles and stretch properties make it relatively easy to handle large font-families; and the bonus is that CSS-3 makes OTF font-features considerably more production accessible, and easy to apply or remove.

In addition all major rendering engines are attempting to handle end-of-line hyphenation to some degree for multiple languages.

Page turns and the Widows and Orphans issue is not handled by any dynamic reflow rendering engine at present. It is still arguable whether line-turns, paragraph turns, page turns and section turns  are a significant issue with reflow content. Turns can be handled with print-like equivalence in fixed-layout ePub documents where something like the print rules may apply, especially if the ePub is a layout mimic of a print book. We have articles to explain and demonstrate this in our fixed layout articles.

Designing for Flow

There is a radical change in thinking required when making the change from print typography to reflow digital content typography. Both the typographic objectives and production methods change. Longing for print-like fixed layout instead of addressing the new flow challenges and opportunities; plus the limited capabilities of reading systems; has held back the development of high-quality presentation for digital content over the past few years. Hopefully this will change and reading systems will make these features available.

With ePub2 digital book design was limited by the capabilities of the lowest performing reading systems and the distribution systems. A very low bar indeed. AZARDI is focused on exploiting the limited CSS set in the IDPF specification AND expanding that to the state of the art CSS-3 specifications.

Very few digital content designers with their brain locked in an X-Y (X=width, Y=height) print world clearly understand that when designing for reflow content the most important considerations are "the line" and "X". Y looks after itself.

Y can be important from time to time with images and blocks, but generally there is little overt control over the behaviour of the Y dimension and a lot of time and effort can be wasted trying to achieve a specific look for a specific document for all devices.

Multi-reader layout equivalence cannot happen and does not happen without some serious design rules being applied and the assistance of processing (or a lot of manual work). It cannot happen at all between monochrome eInk devices and tablets where colour is the new black and white.

The purpose of this Information Unit is primarily to make sure the availability of the various font and related CSS features are known and understood. It does not attempt (too much) to say if, how and when they should be used.