Scaled bitmap export

I would like to export bitmaps of objects in a scaled manner. So I would like 1 pixel in the file to correspond with excatly 1 millimeter in the model. I managed to do this manually by printing to a file. But I would like to automate it in .net or Rhinoscript. But I can’t seem to get the printing automated that way. Preferably a solution that is not limited to the resolution of the display. Perhaps using a render windows?
Thanks, Johan

For anyone who is interested in this topic. It ‘sort of’ worked using a virtual printer driver. But there are a lot of printer settings that you can’t seem to specify using scripting. Additionally, using Rhino 6 my system blocked completely each time when printing many items that way. Didn’t happen in Rhino 5. Anyway, I abandoned the printing idea and ended up using a render window so that I can have higher resolution than my monitor offers. Then passed on the exact dimensions of the object and proportionally resized the high resolution image to reflect to correct size.