Take a look at this.. http://cellosoft.com/2draw/wiki/index.php/Lascaux_Sketch it tells what all the Lascaux tools do and where they are.. try using the blend button with the airbrush (bottom on the brush pallette), and with opacity set about half range.. layering helps too. You can put shades on upper layers and feather the edges to blend using the blur and the eraser set at low opacity.. there's so much you can do with Lascaux..oh yeah when you are using the blend as above..you should also set the flow down about to the same level as the opacity slider.