Filters allow you to control the look of the fractal. There are 11 filters to chose from.
Filters can be used individually or combined to produce a wide range of effects.
My personal favorite is edge detection2. If you want even thinner lines try combining it with
antialiasing. Antialiasing averages the value of pixels near boundaries. It softens images and reduces
Combining edge detection2, antialiasing and embossing, adding starfield can produce interesting results.
XaoS provides a number of tutorials that will guide you visually through the world of fractals.
these are well worth taking a look at.
To access them select
Help | Tutorials