The Sans Twins are a versatile system of sans-serif fonts, featuring both Humanist (Slavko) and Neogrotesk styles (Slavica). This system leverages the linear and minimalist structure of sans-serif fonts to categorize letterforms into three groups: simple shapes, style-defining, and distinct letters. Simple shapes form the foundation of both fonts, establishing proportions and serving as building blocks for more complex forms. Style-defining lettershapes also have a basic structure, with variations defined by stroke endings (vertical or horizontal) and connections (interrupted or continuous), historically linked to Humanist and Neogrotesk styles. Distinct letters provide unique character, ranging from simple to complex forms. By changing these particular letters, the fonts can adopt three specific styles: Expressive, Neutral, or Minimal. With three stylistic sets each, the Sans Twins encompass all major sans-serif styles.