pehehe...I shouldn't laugh, but those are the two most fishy things in Verve combined!

Multiply is just through GL Blending functions, which is not really all that desirable and leads to a bunch of sad results in Verve.
Negative Glossiness leads to a faulty lighting calculation, which just looks cool, so I left it in there, but it generates negative color values, which I clamp away, when you save the image. Great ink-outline trick that borhani loves to take advantage of!

But...if you blend the resulting negative color values, all color-hell breaks lose, of course. Unless you'd want such a thing, of course!

Yeah, I still need to polish the whole thing a bit... and I shall, I promise!
