I made a plexi nozzle yesterday in 1/4" acrylic, just to see if I could do it. It is relatively hyperbolic, but obviously it is hard to tell from the pic.
Bottomside view:
Top view:
Blackeagle is sending me some 1/2" Lexan, which I plan to tap into the top .25", then drill the nozzle below it in the remaining .25". Should make for a relatively simple nozzle design without using multiple layers.