Not bad for an untrimmed 4 month beard. It's probably not going to get "thicker" just longer at this point. In other words, it may never be 100% opaque, at least in the short term. After 4 months pretty much all the slower growers are showing up. It may, however, get significantly better over the next decade or so.

Other than a thicker beard, do you have a goal in mind or a target look you want to achieve?

Patience shall be rewarded!

New beard growers: Check out the Rules of Beard Acquisition.
To upload and post pictures, here is a tutorial.
Do you believe in these Common Beard Myths?