IBM's current "8-bar" logo was designed in 1972 by graphic designer Paul Rand. It was a general replacement for a 13-bar logo that first appeared in public on the 1966 release of the TSS/360. Logos designed in the 1970s tended to be sensitive to the technical limitations of photocopiers, which were then being widely deployed. A logo with large solid areas tended to be poorly copied by copiers in the 1970s, so companies preferred logos that avoided large solid areas. The 1972 IBM logos are an example of this tendency. With the advent of digital copiers in the mid-1980s this technical restriction had largely disappeared; at roughly the same time, the 13-bar logo was abandoned for almost the opposite reason – it was difficult to render accurately on the low-resolution digital printers (240 dots per inch) of the time. The company wrote the IBM initials using individual atoms in 1990, as a demonstration of using a scanning tunneling microscope to move atoms. This was the first structure assembled one atom at a time.
Big Blue is a nickname for IBM. There are several theories explaining the origin of the name. One theory, substantiated by people who worked for IBM at the time, is that IBM field representatives coined the term in the 1960s, referring to the color of the mainframes IBM installed in the 1960s and early 1970s. True Blue referred to a loyal IBM customer, and business writers later picked up the term. Another theory suggests that Big Blue refers to the Company's logo. A third theory suggests that Big Blue refers to a former company dress code that required many IBM employees to wear only white shirts and many wore blue suits. In any event, IBM keyboards, typewriters, and some other manufactured devices have played on the "Big Blue" concept, using the color for enter keys and carriage returns. IBM has also used blue logos since 1947, making blue the defining color of the company's corporate design, which might be another, more plausible reason for the term.