All my graphics are based on sketches then I provide to transform raster drawings into SVG vector format. Using layer technique I can develop artwork like I want to have amazing effects.
If you are interesting about graphic and big potential drawing program inkscape visit www.inkscape.org!
Inkscape is opensourceSVG editor available for Linux, Windows and Mac OSX. Catchphrase? draw freely.
Photo credits: Chiara Ganzer.