The Pencil tool simulates drawing with a lead pencil.
To use this tool...
After selecting the colours you wish to paint with, click on the Pencil button and move the cursor to the point where you want to start drawing. Hold down the left mouse button to draw with the foreground colour; hold down the right mouse button to draw with the background colour. Begin drawing with the pencil by moving the mouse. The size and style of the Pencil can be changed by double-clicking on the Pencil button.