Learn to draw a monochrome landscape using pens and black ink. Follow this link to watch the time-lapse video of making of this sketch.
Understanding values (dark, light and mid tones) is extremely important when sketching/painting, even though the painting may be fully colored.
If you are sketching in monochrome, values help identify various elements from each other.
If you are sketching in colors, values lend a certain jazz, character and contrast to the sketch.
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