Using country polygons for plotting and shading
coast(region=(-6,20,35,52), DCW=(country="FR,IT", fill=(inv_pattern=8, dpi=300)),
land=:lightgray, proj=:Mercator, figsize=11, x_off=5)
# Extract a subset of ETOPO2m for this part of Europe
makecpt(cmap=:globe, range=(-5000,5000,50), continuous=true)
grdimage!("@FR+IT.nc", shade=(azim=15, norm="e0.75"), y_off=11,
frame=(axes=:WsnE, annot=:auto, title="Franco-Italian Union, 2042-45"))
coast!(DCW=(country="FR,IT", fill="red@60"), show=true)
See also GMT ex34