Hi,

Our customer would get transparent function on PDF
(inside in clipped region of PDF also)

I knew transparent function in picture object for bitmap mono color picture, that not available when used PDF as background or overlay object, however.

Regards,

The PDF is transparent by default at output time. You can't see it in PlanetPress Design (because it gets displayed as a bitmap) but that's only while you're designing your template. When you actually run the job (or generate a preview), then you'll notice the PDF is transparent (assuming, of course, that your original PDF was generated with transparency... otherwise, there's nothing we can do about it!)