render/ material/ set object->background set into BG picture: image mapped->alpha set into BG movie: image mapped->alpha (for aspirin99) render options poser4 render no antialias (I can not make it work on firefly render) And of course: File->Export->Image and select a format such as .tiff or .png these save an alpha channel with them, unlike .jpg thank you very much, Karen1573, you help me. I need your advice, you save me many hours of post render work. Thank you again Your happy Fabio