Founded in 1992 by Qian Ni — a Beijing-born flutist and Boston University School of Music graduate — Eastman began as a string instrument company producing violins, violas, cellos, and basses modeled after traditional German luthier workshop methods. Headquartered in Pomona, California, the company expanded into archtop guitars in 2002, steel-string acoustic flattops in 2008, thinline electrics in 2012, and solidbody electrics in 2016. All instruments are handcrafted in dedicated workshops using hand tools — chisels, files, gouges, and planes — rather than CNC-driven assembly lines, a distinction Eastman considers central to its identity.

The guitar lineup spans acoustic archtops, dreadnoughts, grand auditoriums, parlors, classical and Gypsy Jazz models, thinline hollowbodies like the Romeo series, and solidbody electrics including the SB59 and Juliet. Eastman also produces mandolins in both A-style and F-style configurations. Notable features across the range include thermo-cured (torrified) tops, the Truetone polyurethane finish, and the Tonetight detachable neck system developed in partnership with Dana Bourgeois. Eastman is the parent of Bourgeois Guitars, acquired in 2019.

Eastman has built a reputation for delivering handcrafted build quality at price points well below comparable American and Japanese instruments, earning a strong following among jazz, indie, and roots players. Artists associated with the brand include Jeff Schroeder of the Smashing Pumpkins, Adrian Utley of Portishead, James Williamson of Iggy Pop & The Stooges, James Dean Bradfield of Manic Street Preachers, Kyp Malone of TV on the Radio, and Peter Stroud, longtime guitarist for Sheryl Crow.

Eastman has 183 products cataloged on Equipboard, including Steel-string Acoustic Guitars, Semi-Hollowbody Electric Guitars, and Acoustic-Electric Guitars. Their gear is featured by 38 artists, with the strongest followings in Rock, Pop, and Jazz. Notable users include J.B. Meijers, Dave Lincoln, and Brett Simons. Most Eastman products sit firmly in the high-end, boutique range.