Contours are quite fiddly to create involving a lot of acquiring and processing of data,
Mapupuloader4 includes Tool that simplifies the process of creating contours for a given area and imports the results into Basecamp or direct into your Garmin.
Thickness,texture and colours of contour lines
Contours are saved as 0x21 and 0x22 : To change the default colours,pattern (ie dots) & thickness of contour lines you need to add these polylines to your TYP file - TYPWiz can do this quickly.
On nuvis contour lines can look too chunky and quite ugly. Change the pattern to a dotted line and set zoom level (resolution . if your using mkgmap style files) to a higher number.
|Part of Haldon Hill on Mapsource|