The False Nut Upon the Road

I've been fiddling with false nuts, reverse capos, or whatever you call them. Details follow the picture below.

This one has a pair of notches for capoing two strings and a third notch between them for capoing a single string. The end nearest the melody strings is cantilevered out to allow a little extra clearance for the noter when capoing two strings.

The single-string notch is placed a little further inboard so that the thing doesn't try to squirt out from under the string owing to the cantilever.

A leather thong and screw-eye help me keep track of it.

Other things being equal, putting on a reverse capo increases string tension, thereby making the capoed string too sharp. You can compensate for this by setting the string-bearing edge back from fret just enough to give true pitch when you slide the capo into place against the fret. Unfortunately, the compensation works properly only on a single instrument and only on two or three closely spaced frets.

This one is ground so that it gives a true pitch on the third and fourth frets of my Kudzupatch Galax.