Font Scaling Facilities
As Reading Distance and Tablet Orientation preferences can vary from user to user, fixing an optimum font size can be difficult. As a result, some services provide Font Scaling Facilities to allow the user to control font sizes to suit their reading behaviour.
A Font Scaling Facility is usually accessed from a navigation panel at the top of the screen. When activated, this should display all of the size variables available, with the current selection clearly indicated. The example shown below left, is for reference only and is not a GEL design template.
Body font scaling measures
Body font scaling measures are usually defined as Extra-Large, Large, Medium, Small and Extra-Small, rather than using numerals. The following are recommended type sizes for each measure.
As mentioned previously, increasing and decreasing font sizes will affect the optimum reading line length (usually set to a limit of 12-15 words).
Ideally, column width and leading should also adjust to the changes in font size.