Grez Guitars is a boutique instrument workshop based in Petaluma, California, founded by luthier Barry Grzebik. Before turning to guitar building, Grzebik spent decades as an acoustic engineer at Apogee, designing sound systems for events like the Grammy Awards, the Oscars, and the Olympics. He brings that rigorous approach to acoustics into every instrument, favoring minimal glue joints, solid wood construction, and asymmetrical body designs to maximize resonance.

The brand is best known for its semi-hollowbody electrics, particularly the Mendocino — a lightweight, compact instrument that bridges the tonal gap between an ES-335 and an archtop. The lineup also includes the Folsom solid body, the Grand Tour acoustic, baritone and 12-string Mendocino variants, and bass models including a Bass VI. A hallmark of Grez instruments is the use of reclaimed old-growth California redwood — sourced from deconstructed train tunnels, wine barrels, water tanks, and barns — for tops and tonewoods. Grzebik also carries on the archtop building tradition of the late R.C. Allen, whose shop tools and techniques he acquired.

Grez instruments are played by artists including Jeff Tweedy, Leo Nocentelli, Ryan Bingham, Jacob Tilley of Young the Giant, Kid Andersen, Justin Corgan of the Allman Betts Band, and blues guitarists Little Charlie Baty, Nick Moss, and Laura Chavez.

Grez Guitars has 1 product cataloged on Equipboard, including Hollowbody Electric Guitars. Their gear is featured by 1 artist, with the strongest followings in Blues and Jazz. Notable users include Tim Lerch.