Problem with Toon lines V-Ray for Rhino

[emilymartinez]

Hi,

 

I am trying to render these objects as black with white lines to look like flat graphics. It works except I have some issues with double lines and it looks like the lines don't meet at some corners correctly. This is driving me nuts. Is there anything I can do to fix this?

 

I just made this model by Boolean differencing one box out of another. It's not constructed face by face. No idea why the lines are acting up on such a simple shape. Any advice would be so awesome! Thanks in advance.

 

Check out these two images.