Adobe Illustrator Share shape edges

Question

I am relatively new to Adobe Illustrator, so I am not very familiar with the tools.

I have two paths, with stroke inside selected for the stroke method. I would like to have the two shapes share an edge (the thick one), so the thick edge will be normal thickness rather than twice as thick.

The picture in this post has a picture which shows two shapes sharing an edge, but with different fills. How do I achieve this?

Answer 1

First draw your shape as one object. Then grab the pen tool again and draw a center line from the left end point to the right end point.

Select both the shape and the path in the middle and go to the stroke options. Make sure the stroke is center align. I picked 4 pt black stroke for my example.

What that looks like

I then went to expand appearance. I then selected all and used the pathfinder options and clicked on divide.

Delete the ends with the direct select tool. Also use direct select tool to change color of bottom shape.

Result