Yeah, you guys are right about Paul's Iceman.
They tried to simply break a mirror, but unfortunately, it doesn't break in perfect pieces.
You get everything from large sheets, to small "crumbs" of mirror that you need to glue back together.
Not very practical to work with, plus it may not look as "cool" as you though it would.
It seems to me that the best way is to cut it, so that you can get the perfect design.
But I think you really need to angle/adjust the pieces so that they just don't lay flat together.
If you don't, I don't think the "break" will really look like much...
It has nothing to do with refracting lasers or anything like that, but I just don't think it will stand out much if you leave it "perfectly" flat.
And if you angle the pieces:
They noticed when doing Paul's guitar that even when cutting, the edges (where the breaks are) are razor sharp, so they ended up grinding down the edges slightly, giving it a minor bevel.
It sounds like alot of work, so I can understand why it costs quite a bit to have it done......