What are they for? Do you make sigs with them? I've tried but they dont turn out that well. Or is it for making stuff in c4d?
Wireframe renders are normally put on 'Multiply', as this gets rid of the white background, leaving just the black lines. Then, it's used in whatever you want. They can be used in sigs, LPs, anything.
People usually use them in tags or LPs. If you can work them, they add some pretty neat effects as seen in some of Skystrife's work. People shrink 'em and add different colors to them in C4D to be used beyond just b&w.