Puedes buscar en google: Orcad Layout negative printing.
O puedes leer lo siguiente:
Creating negative image prints of copper layers to create board prototypes
PROBLEM:
In Layout, how do I create negative image prints of my copper layers to create an in-house prototype?
SOLUTION:
From within Layout, choose the Post Processing toolbar button. From the menu that displays, choose Setup Batch and enable Extended Gerber output for your layers. If you are hand-drilling the board, select the Keep Drill Holes Open option to leave an opening in the center of your pads as a drill target. Run batch post processing (choose the Post Processing toolbar button and then choose Run Batch) to create your extended Gerber files and your GerbTool .GTD design file.
From within GerbTool, open your .GTD design file. Double-click on the rectangular Draw Color block and set it to white. Then, double-click on the rectangular Flash Color block and set it to white as well. From the File menu, choose Page Setup and select the Print Background and Color/Gray Scale options. Make sure the Overlay and Sketch options are not enabled. Finally, print the layer by choosing Print from the File menu.
Como verás todo el tema está en la herramienta Gerber. Puedes estar seguro que funciona pues yo lo hice. El único problema es que gastarás mucha tinta de tu impresora laser.
Saludos
