Charis is highly readable and holds up well in less-than-ideal reproduction environments. It also has a full set of styles - regular, italic, bold, bold italic - and so is more useful in general publishing than Doulos SIL. Charis is a serif, proportionally-spaced font optimized for readability in long printed documents.
The goal for this product was to provide a single Unicode-based font family that would contain a comprehensive inventory of glyphs needed for almost any Roman- or Cyrillic-based writing system, whether used for phonetic or orthographic needs. In addition, there is provision for other characters and symbols useful to linguists.
At least, that is what is said by SIL International, who released it under SIL Open Font License.
Try and print it on your personal laser printer or at your neighborhood’s copyshop!