Stationery is the name given to materials needed for written and print communications, especially in business, companies, and organizations. Office supplies such as letterheads, envelopes, pens and pencils, notepads, etc. 

Stationery design, then, refers to applying custom graphic art to these items as part of a branding strategy, to make them part of a brand’s image commonly including logo design, name, and slogan plus graphic elements to make them pop.