If you’re familiar with the process of downloading and installing font files, you’ll know that you need to download a different font file if you want a Bold vs. Regular. Each font file specifies the weight or style of a typeface. For example, in the fonts folder on my hard drive I have 14 different files for the typeface Adelle. Each of these font files specifies a font for the typeface Adelle. If you don’t know the technical difference between the term font and typeface, read our blog post.
Problems arise when different designers have font files for the same typeface that are labeled differently. Design programs will think the font is missing from the program if one designer has “Adelle_Heavy.otf” installed on their machine, and another has “Adelleheavy.otf” installed. Also, the “Heavy” version of Adelle might be very thick compared to the “Heavy” version of Whitney.
Recently Variable Fonts have been introduced. A variable font lets the graphic designer adjust the weight/thickness of a font as well as the spacing giving more control to the designer to achieve some really cool customization.
How come all fonts aren’t variable? Fonts are created by type designers. Type designers very carefully craft the different fonts to provide a series with contrast, readability, and what works best with that particular typeface.
To adjust variable spacing and weight of a variable typeface, open the character properties panel in Illustrator, and you’ll find a small icon indicating that the typeface is variable. The elements that can be adjusted depend on what the type designer has made available. For example, in this screenshot Source Sans Variable lets you adjust the weight only.
Some additional information on Flexible Fonts is available on the Adobe website.