An Old High School Project

So while doing a little sketching yesterday I stumbled on an old project I never finished. I thought it looked pretty fun so I started adding some depth to it (I wasn't very good with adding dark colors in back in High School). You can see how lightly I used to draw, and then in what looks like an outline around the teeth you can see how deep its gonna be when I'm done with it! You can get the idea of how the whole inside of the mouth (for lack of a better word) will be by looking at the top right corner. I'm pretty much done up there (I think). So here's a quick look at it (the before). I'll re-post it when its totally done (the after).