Mike some of the filters do what you are describing, and some fill the shape. I'm still trying to come to terms with it myself and don't know how to tell the difference, but there is one. I was messing around with one and changed something, gave a unique name and saved it, but that particular filter I created would only create a rectangular area and would no longer fill a shape. I for one need to spend more time with it and figure it out. From what I have seen the tutorials Frances did are among the best.