1. A method of halftone image reproduction of images on a transparency medium comprising the steps of: providing transparency medium including a substantially transparent carrier with a first ablative coating and a second ablative coating having respective first optical density and second optical density to light transmittable through said medium; providing a scanning beam of ablative radiation having variable intensity; scanning the beam of ablative radiation in successive line scans of sequential pixels of image information across said first ablative coating in an image field while modulating said intensity of said radiation beam as a function of the image information of each line scan in order to ablate or leave intact said first coating at each of said sequential pixels scanned; and repeating the above steps with respect to said second coating to provide halftone optical of said sequential pixels.