A method of processing print data includes the step of maintaining a buffer. Rendered image and graphics objects in a contone layer from a graphics system together with a black layer are received into the buffer. Obscuration of black pixels of the black layer by objects placed on the contone layer is detected. Obscured black pixels are composited with the contone layer if interaction between the black pixels and the contone layer is possible. The contone layer is converted into CMYK specific to a printer. The black layer and the contone layer are compressed and packaged into a page description to be delivered to the printer.