Once I've "closed the box", the next step is to add binding to the edges. Binding serves several purposes - it provides strength and protection to the edges of the guitar and it looks nice.
Before binding can be added, the sides have to be sanded smooth and even. I use a "rolling pin" sander to do this. I always do it outside of my workshop because it makes so much dust.
The binding sits in a channel that is routed out of the sides. This is very tricky to do and requires lots of careful measuring and checking. One slip of the router can do significant damage to the top or the sides.
I use a jig that holds the router vertical. The body sits on a carriage that allows me to rotate it beneath the router. The router bit has a spacer to make sure it doesn't cut too deeply into the sides. It can take an hour or more to get this all set up just right.
In the picture you can see the ledge being created by the router.
Surprisingly, many expensive factory guitars use plastic binding. This makes sense - it's easy to bend and handle. Personally, I think it looks tacky and I always use solid wood bindings. Wood bindings need to be bent to the shape of the sides - and so the side bender gets another workout.
A recent build actually has a binding and a perfling strip. The strip has a pattern and sits on the top of the guitar. The binding sits on the edge. Perfling provides a decorative element, but doesn't really do much more.
Glueing the binding is an almost comical process. You have to hold it in place, apply glue, and then use special tape to temporarily hold it in place. I've not worked out an elegant way to do this, but somehow it gets done!
Once the binding is glued in, it gets sanded and scraped so that it is roughly smooth. Then the body gets put to the side and I start working on the next major part - the neck.