z=y^2-x^2 Trying to render these sheets by hand is very difficult for me. I can conceptualize the sheet in general by observing that the trace in z=y^2-k^2 follows the trace of z=k^2-x^2 as z tends to negative infinity. The opposite is also true as z tends to infinity. This information combined with the hyperbolic traces gives me a general idea of the sheet. Any tips in how to draw this.