Putting stroke over brushes?
So I wanted to make a frame out of bubbles for some text. I made a custom brush and made this.

But I wanted to bring more attention to the bubbles because they look pale when printed out.
So the idea is to put a border around these tiny bubbles and I decided to put a outside stroke over the thing. But instead of making a thin black line around each bubble, it made this:

Just to test it out on another thing, I just pulled a simple line with a normal brush and stroking it gave the similar results. It seems to happen with every object that has less than 100% opacity.
-stroking a brush and stroking a pencil
So I wonder how do you properly stroke a brush (or any object with less than 100% opacity)?
