This tutorial teaches how to use masking in Adobe Flash by having the user import an image, place it on the stage, create a motion tween of a circle graphic moving across different locations on top of the image, and then applying a mask to the circle so that it reveals parts of the underlying image as it moves. The steps include importing an image, placing it on one layer and the circle on another layer, tweening the circle's motion across multiple frames, and finally applying a mask to the circle layer.

1. Tutorial 6: Using Masking
1. Open a new flash file. On Layer 1, click on Frame1.
2. Click File > Import > Import to Library > choose any image. The image will
automatically import to flash library.
3. Click on Window > Library.
4. Click and drag the image from the library to the stage.
5. Name the Layer 1 as a picture.
6. Right-click on Frame 60 > Insert Frame.
7. Insert new layer, name it as a circle.
8. Click Frame 1 layer circle, then draw a circle. Convert to Symbol as a
graphic (name it as a ball).
9. Right-click on Frame 10 on layer circle, and then choose Insert Keyframe.
10. Right-click on any frame between Frame 1 to Frame 9, choose Create
Motion Tween. Make sure as shown below.
11. Click on Frame 10, drag the circle to other location.
12. For Frame 20, 30, 40, 50 and 60, insert Keyframe and Create Motion
Tween. Drag the circle to different location.
13. Right-click on the layer circle, choose Mask.
14. Save the file as a Tutorial 6.