When I paint direct from nature, I always try to seize what is essential by means of line. Then I fill up the defined spaces(whether they have been expressed or not; for they have been felt at all events) with simple flat tones: all ground or soil will contain the same violet tone, practically the whole of the sky will be kept blue in tone, while foliage will be blue-green or yellow-green(either the blue or the yellow may be deliberately intensified) in short, no photographic imitation, that is the chief thing! -Vincent Van Gogh- -Letter to Emile Bernard-