****I AM NOT RESPONSIBLE FOR ANY DAMAGE THAT YOUR GUITAR INFLICTS IF YOU DON'T DO THIS RIGHT****
This only works if you have a gloss finish on your guitar.
also don't do this to acoustic guitars, i don't know if it will come off.
Step 1: Go for It
You can use this if your like a professional musician for gigs and such things or if you want to freak out your parents into thinking you drew all over your guitar.
To get it off just use your finger or a dry-erase board's eraser.