Artists have used lines to make drawings for thousands of years. Some of the earliest examples of drawing come from the simple outlines found in ancient cave drawings. As drawing moved from cave walls to paper, artists like Rembrandt van Rijn began to carefully arrange lines to create highlights and shadow, creating realistic sketches. Other artists, like Camille Pissarro, use lines to create three-dimensional spaces on flat surfaces. Contemporary artists continue to build upon existing drawing techniques. For example, Janet Fish uses dense layers of color to create still-life drawings. But while techniques have changed over time, the line remains the foundation of drawing.