[citation needed] The structurally similar naturally finished J-50 first appeared in 1942, but did not enter continuous production until 1947.

Introduced in 1942 to replace the inexpensive Great Depression-era flattop J-35, the J-45 standardized the company's approach to the dreadnought guitar.

With a list price of $45, it nonetheless initially only varied slightly, with strengthened internal bracing and a new teardrop-shaped pickguard.

Although a few triple-bound top types were initially produced, the standard single binding was simple, soundhole ring austere, and neck only sported modest dot-shaped mother of pearl fretboard position markers.

Gibson produced a handful in 1942 using high quality wood laid up before World War II-induced shortages took hold.