Hi, I had an idea to show the direction of the slope in elevation data contours. To implement this, I made a small modification in DEM.java so that contours are always created in the same direction: http://koti.kapsi.fi/jpa/stuff/other/patch-contour-direction Then I just used the bitmap mode in the TYP editor to make small arrows that point downwards: http://koti.kapsi.fi/jpa/stuff/pix/contours.jpg This patch could be added to the main branch, and the TYP file then specifies whether to use arrows or not. Currently the contours start in random direction depending on the shape of the area. -- Petteri Aimonen PS: Thanks for the great program!