alpha csv wkt,halo-opacity,text-opacity,opacity "LINESTRING(0 0, 10 2)",.1,.1,.1 beta csv wkt,halo-opacity,text-opacity,opacity "LINESTRING(0 2, 10 4)",1,1,1 gamma csv wkt,halo-opacity,text-opacity,opacity "LINESTRING(0 4, 10 6)",1,1,1