White nylon plastic with a matte finish and slight grainy feel.
This is a collection of common example surfaces from classes in multivariable calculus. Much larger versions of these surfaces are available here.
Contour lines, together with 8 radial curves make up the surfaces. All surfaces are plotted in such a way to show values of z in [-2,2]. The hyperbolic paraboloid is further cut along a cylinder of radius sqrt(2). The equations of the surfaces are: