The small rectangular object next to the abc button on the Icon Editor control area is an eraser. The icon for the eraser is shown in Figure 15-11.
To erase a portion of an image:
Click SELECT on the eraser icon.
Move the pointer to the area in the canvas window that you want to erase.
Press SELECT and drag the pointer over the area you want to erase.
If you lift your finger from the mouse button frequently to end the current input segment, you can undo the last segment at any time without losing all of the changes you've made. You can undo the last input (erase) you made at any time by choosing Undo from the Edit menu, or from the pop-up menu in the Icon Editor window pane (canvas).