1. File > Import > Import to Stage to get “sideMountain” file onto the stage.
2. Rename the Layer 1 “mountain”
3. Lock the mountain layer, and add a new layer > rename it xboarding.
(make sure the xboarding layer above the mountain layer)
4. Drag an instance of the symbol to stage from library, place the X above the snowboarder.
5. On the xboarding layer: Modify > Timeline > Layer Properties or double click xboarding layer to open the Layer Properties box.
(check the Mask radio button, then OK)
6. Double click the mountain layer: check the Masked radio button.
7. On Frame 36, press F6 for xboarding layer, then lock it.
8. On Frame 36 press F5 for mountain layer.
9. Move the playhead back to Frame 1, select the xboarding symbol on the stage,
and move it out off the stage to the left.
10. On Frame 1: Modify > Transform > Flip Vertical.
11. Make a Motion Tween for the xboarding layer.
12. Lock the xboarding layer to check the masked effect.