A contour line defines the outline of a form, as well as interior structure, without the use of shading. A fundamental basis of drawing, contour lines are usually the first technique children adopt to draw people, houses, and trees. A simple contour line can create a form with minimal embellishment while allowing for a range of line quality. A reliance on contour line shaped the style of Ancient Greek red figure vases, while figure studies from the Renaissance, such as those of Michelangelo Buonarroti and Leonardo da Vinci, reveal clearly defined lines and naturalistic depictions of the human figure. Japanese Ukiyo-e prints, with their strong emphasis on flat planes of color delineated by dark lines, such as those by Kitagawa Utamaro, influenced the drawings and prints of European artists in the 18th and 19th centuries; these artists played with contour lines to create expressionistic visions of the human body, reflecting their interest in motion, mood, and subjective forms. In works by Edgar Degas, Henri de Toulouse-Lautrec and Egon Schiele, the contour line shows its mutability, becoming sinuous, angular, heavy, faint—sometimes all within the same work. Today, comics, cartoons, manga, and anime, which now incorporate both hand-drawn and computer-generated lines, carry on the tradition of emphasizing contour lines.