gibson introduced the southern jumbo also known as the southerner jumbo or sj guitar in 1942, as a more "deluxe" version of its popular but plain j-45 model. it featured a sunburst spruce top, mahogany back and sides (a few rare early examples had rosewood back and sides, or rosewood sides only), rosewood bridge and fingerboard, with gibson's "deluxe" split parallelogram pearl inlays. from 1947 onwards the model also featured a white bound fingerboard, in contrast to the plain (unbound) fingerboard of the cheaper j-45 and its sister (natural finish) j-50 instrument.