Typography

Carbon uses type tokens across two type sets to manage typography. Type tokens are pre-set configurations of typographic elements such as font size, weight, or leading (line height) that are specifically calibrated for use alongside IBM Plex in product. Selecting the appropriate type style is determined by layout or template structure. Layouts may have several levels of architecture or areas that require varying typographic hierarchies.

The productive type set is primarily used within product spaces, where users benefit from a more condensed treatment of content to maintain focus on tasks. The productive styles work together to support the hierarchy of information and set user expectations. On the other hand, the larger expressive type styles allow for a more dramatic, graphic use of type in editorial and marketing design. These type styles are excellent for long form reading and scanning, but would be distracting for use in product.

Within Body styles and Utility styles, the same set of styles are offered. Productive styles are named with a suffix of -01 and expressive style names have a suffix of -02.

There are two heading sets and the major difference between them is in how they are implemented in code. The productive type set uses fixed headings. Expressive headings are responsive and the type styles change size at different breakpoints.

For more detail, see Styling strategies and Type sets.

Carbon uses the open-source typeface IBM Plex. It has been carefully designed to meet IBM’s needs as a global technology company and reflect IBM’s spirit, beliefs, and design principles. IBM Plex can be accessed and downloaded from the Plex GitHub Repo.

The IBM type scale is built on a single equation. The formula for our scale was created to provide hierarchy for all types of experiences. The formula assumes that y₀=12 px.

Typography creates purposeful texture, guiding users to read and understand the hierarchy of information. The right typographic treatment and the controlled usage of type styles helps manage the display of content, keeping it useful, simple, and effective.

Font weight is an important typographic variable that can add emphasis and differentiate content hierarchy. Font weight and size pairings must be carefully balanced. A bold weight will always have more emphasis than a lighter weight font of the same size. However, a lighter weight font can rank hierarchically higher than a bold font if the lighter weight type size is significantly larger than the bold one.

We suggest using IBM Plex Light, Regular, and SemiBold for digital experiences. The semibold weight is ideal for section headers, but should not be used for long text.

Each weight has an italic style, which should only be used when you need to emphasize certain words in a sentence (titles of works, technical terms, names of devices, and captions).

Type color should be carefully considered, with legibility and accessibility as paramount concerns. Keep type color neutral in running text. Use primary blue for primary actions.