Jérôme Thibouville-Lamy (JTL) was a  musical instrument manufacturer founded in 1869 in Mirecourt, France. It was formed from an older Mirecourt firm, Husson-Buthod-Thibouville, when Louis Émile Jérôme Thibouville married Marguerite Hyacinthe Lamy and he renamed it using their combined names. JTL grew to become one of the biggest makers of trade violin family instruments, but also made brass & woodwind instruments as well as organs and guitars.

Source: JTL website