Negative-to-positive conversion transforms dark-mode PDFs, microfilm scans, inverted CAD schematics, and inverted architectural drawings into standard black text on pure white paper. The engine maps RGB color channels along the perceptual luminance axis, inverting dark backgrounds while preserving colored line contrast. Printing a document with a solid black background consumes massive quantities of black printer toner and causes heavy paper saturation. Inverting negative PDFs to positive white backgrounds reduces printer toner consumption by over 90% and produces crisp, legible physical printouts. Widely used by engineering teams working with CAD exports, researchers reading dark-mode scientific papers, and students printing dark-theme study slides.