https://commercialtype.com/catalog/duplicate/duplicate_slab

When Florian Bachleda requested a serif companion for Duplicate Sans for his 2011 redesign of Fast Company, Christian Schwartz decided to take the most direct route. He simply added slabs to the sans in a straighforward manner, doing as little as possible to alter the proportions, contrast, and stylistic details in the process. Because its skeleton is neither geometric nor traditionally humanist, Duplicate Slab has warm and informal texture that is atypical of a slab serif. The family manages to be quite pretty in its lighter weights and both friendly and forceful in its heaviest weight.