To create Page Curl effect click Deformation | Page Curl or select Page Curl folder.
On the Shading panel you have the choice to use:
the Foreground or Background color;
the shade under the curl;
the value of shading transparency.
On the Background panel you can choose to use Foreground color or background color.
You can choose to Keep the image under the curl.
On the Orientation panel you can choose the Vertical or Horizontal alignment of the curl.
On the Location panel you can choose the corner on which the curl will appear.