The font size choice is a main item within readability. Because of its importance, here we are dedicating a chapter to it.

 

The font size will depend on two factors. The first is the typeface itself. For example, if it has a small x-height it may be necessary to increase its size. The second factor is the device itself. In her book "Type on Screen" Ellen Lupton explains that computers are usually farther from the user's face than handheld devices , such as books or mobile phone. Letterforms appear fuzzy  because of low pixel densities and backlighting, do not mix these problems by adding a very small typography.