What font does IBM use?

IBM ran on Helvetica for decades, which meant paying to sound like everybody else who also ran on Helvetica. Plex was the answer: a family designed in-house by Mike Abbink with Bold Monday, released in 2017, covering a sans, a serif and a monospace so that a company that writes code, contracts and advertising can do all three in one voice.

The shapes carry an argument about the company. The sans has a slightly squared skeleton that comes from the engineering side of the business and a humanist italic that comes from the drawing side, and the mono was treated as a first-class member rather than as the sans with the letters pushed apart. Whether you buy the story or not, the family is unusually complete and unusually well made for something given away.

The eight-bar IBM logo is not Plex and never was. It is Paul Rand’s 1972 striped mark, built on his own 1956 slab-serif lettering, and it is a drawing — no typeface reproduces it. Plex is what the rest of the company is set in.