Use type styles (fonts) and font sizes that are easy to read but don’t use more than 3 different types otherwise your sign will look messy and cluttered.
At this stage the layout and arrangement of your text has been carefully considered but so must the type style. Avoid eye-straining fonts like brush script in preference for simple readable styles. Calibri, Arial and Garamond are fine but Activ Grotesk is frequently recognised as the most readable style.
Next, focus on font size. These are suggested pyramid of font sizes for the different components of your sign:
Main title/theme 72-100
Main text 32-48
Subtexts and detailed text boxes 24-30
Ideally, your sign should appeal to young and old, non-specialists and experts. As a result, try to design your text and graphics to be understood by a 13-year old. Keep to plain, simple, jargon-free language (although you can cater for experts with more detailed text boxes).
Typically, for western languages, the standard practice is to leave a ‘ragged right edge’ (text 2). Apart from feeling familiar, this layout has a useful psychological advantage. Some lines are short while others are longer. If a visitor reads a short line, they will be more inclined to read the next line, which might be longer, but then the line after that is shorter so they say to themselves, “That’s no problem, it’ll be quick”, and so on.
If the text is justified on both sides (text 1), it looks visually daunting, a bit like reading a scientific research paper. Most people won’t even try, will not read to the end or if they do the words will have less impact as their attention drops.
It’s a bit like mind games.