I know in the 60's gibson offered the closed moustache brdige with inlays on the sides.īut I don't know when they first offered the 2 ribbons(1989?). I know most if not all the vintage guitars I've seen ( 38's 40's and 50's) had 4 ribbons When did Gibson start offering the 2 ribbon bridge ? Given the same neck set angle, a 2-ribbon bridge will allow for lower action adjustment than will a 4-ribbon bridge. A 2-ribbon bridge better accommodates a shallow neck set angle than does a 4-ribbon bridge. A shallow neck set (underset) does not leave as much room for a short saddle without giving up adequate string break angle over the saddle. An overset neck (fingerboard angled down and away from the plane of the guitar top) allows for more saddle lowering and better accommodates action adjustment on a 4-ribbon bridge as the steeper neck angle allows for a taller saddle. And here's where neck set angle comes into play. The higher starting angle allows for more saddle shaving to lower action. Lowering the saddle in both cases will decrease string break angle over the saddle, but the 2-ribbon setup has a higher angle starting point than does the 4-ribbon. It's this distance that makes the difference in how much saddle lowering can be done while maintaining adequate string break angle. This placement makes for a steeper string break angle over the saddle than does the pin and saddle positions found on a 4-ribbon bridge, which you can see in the photos is more than twice the distance of the 2-ribbon design. The 2-ribbon bridge places the pins much closer to the saddle. (Yes, the ribbons are missing but you know where they go!) It's this distance that makes the difference in how much saddle lowering can be done while maintaining adequate string break angle. (No disrespect to Parlorman!) Hopefully this will clarify things for the unintiated. There are likely some that may be confused or don't understand the geometric differences between the two with respect to action adjustments possible. There's been some discussion lately concerning the two different bridge configurations found on the SJ200: 2-ribbon and 4-ribbon.