Definition:
A sketch is painting or drawing capturing the essence of an object or scene, giving an idea or outline of it or simply a part thereof. How quickly or slowly a sketch is completed depends on the individual artist. Some work very quickly and roughly, others slowly and in great detail.
A sketch can also be a study for a future painting, done to investigate composition, color, tone, etc. such as these figure studies.
Any medium can be used for sketching, though pencil, pen, and watercolor are the most commonly used. There's no rule for the size a sketch needs to be either, sketchbooks range from pocket-size upwards. Usually they're smallish to make carrying them around easier.
See Also:
- How to Sketch
- Venice Sketchbook Pages
- Pages from my Pocket Sketchbook
- Best Painting Sketchbooks
- How to Keep a Sketchbook (From About.com Drawing/Sketching)
