Any item you write with will make a guitar capo.
Guitar capo pencil and rubber band.
Simply lay the writing implement across the frets and string something stretchy over one end and behind the neck to the other end so the pencil is pulled down tight across the strings.
A simple pencil and rubber band will work well as an emergency capo.
Learn how to make a diy capo in this quick tutorial.
If you don 39 t have a capo or if you just forgot to bring one to your jam session you can quickly put one together with just a pencil and a couple rubber bands.