D-type guitar:

D-type guitars are generally 41-inch standard guitar bodies, which are the kind of guitars we often see on TV. As you can see from the picture, this type of guitar has relatively flat lines and a relatively large body, so it has a good resonance effect, a loud sound, and a heavy bass and bright treble, which is suitable for singing and accompaniment. The D-barrel guitar has a larger body, excellent resonance, and deep bass, which is suitable for playing and singing.

JF-type guitar:

The JF-type guitar is a collapsed shoulder and corner design. The domestic JF barrel was invented by Mr. Guo Yulong, a domestic luthier. Compared with the traditional corner angle, the angle is larger, the cost is lower when bent, and the cost is saved. The unique appearance distinguishes it from other common barrel types and finger-style guitars. The tone and playing take into account the D-type guitar and the OM-type guitar.The JF-barrel guitar has a larger waist curve than the D-barrel guitar, and its sound is concentrated, which is suitable for finger-playing.

—Aiersi JF body Acoustic Guitars —

About designer Yulong Guo . he is is the first chinese guitar luither won prize at Granada Guitar Festival Spain  . about luthier  , more details from web https://www.aiersiguitar.com/?p=23398