At this point, save the file, then delete the GuideLayer,
we don't need it anymore. If you have done everything
correctly at this point, the AnimLayer should look like
Make a new layer, name it AnimLayerMask.
Duplicate the content of AnimLayer into AnimLayerMask.
Arrange the layer so that AnimLayerMask is located
Make yet another layer, name it: ImageLayer.
Arrange the layers so that ImageLayer is in the middle
of AnimLayerMask and AnimLayer.
While ImageLayer is active, import a jpg file, then
position and resize it so that it fits within the paper. (Hide
AnimLayerMask so you can see the image.)
Hide all layers except AnimLayerMask.
Go to Frame 1 of AnimMaskLayer and delete color-fill on
the non-gray colored area, also delete the diagonal line on
the bottom-right (see below).
Go to Frame 20 of AnimMaskLayer and delete the
color-fill on the non gray-colored area (see
On Key frame 21 and 40, delete everything, except the
The purpose of this exercise is to create a mask so that
the image on front side of the paper will show through
Click on AnimLayerMask, then make it a Mask layer.
If you go to frame 10, this is how it should look like.
What is going on?
Here's a little trick with mask.
Test the movie.
You can easily reveal another picture behind the
paper. See here.