A while ago it caused major slow downs in the viewport, depending on your video card. Ever since I've stayed away from it.
In regards to the question, why are you rendering a colored object in grayscale? Anyways, make sure that your renderer's filtering setting is turned off, as this will add anti-aliasing. Eg for Maya Software, make sure that multi-pixel filtering is turned off.
Imagination is more important than knowledge.
Last edited by NextDesign; 04-06-2014 at 07:59 PM.