MJT Aged Guitars is a family-owned shop based in Carthage, Missouri, founded by Mark Jenny on California's Central Coast more than two decades ago and later expanded with his son Matt Jenny. The company specializes in vintage-style nitrocellulose lacquer finishes and relic'd guitar bodies and necks designed to mimic the look and feel of well-worn instruments from the 1950s and 1960s.

MJT works exclusively with 100% nitrocellulose lacquer, hand-mixed in the colors Fender used between 1950 and 1965, and applies a proprietary aging process that condenses decades of natural wear into a few weeks. Levels of aging range from "Closet Clean Wear" to "Super Heavy Wear," and customers can order finished bodies, necks, partscaster kits, or complete guitars and basses across a range of T-style, S-style, J-bass, and P-bass models (designated VTT, VTS, VTJ, VTC, JBT, PBT, and others).

The brand has built a following among partscaster builders and players chasing an authentic vintage aesthetic, and is widely referenced in online luthier and bass-building communities for its finish work, custom-color matching, and refinishing services.

MJT has 5 products cataloged on Equipboard, including Solid Body Electric Guitars. Their gear is featured by 4 artists, with the strongest followings in Rock, Blues, and Metal. Notable users include Brad Delson, Chris Buck, and Christian Lembach.