He specifically set a constraint for now curved surfaces. Using cylindrical and conical surfaces would have violated that constraint.

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mkl 3 days ago | parent [-]

But that's an arbitrary constraint choice that didn't need to be there. It's not inherent to the medium. He has a justification for it (curves are "flimsy and introduce variances") but that is easy to get around with perpendicular reinforcing pieces inside that constrain the curve.

	▲	zaphar 3 days ago \| parent [-]
		Arbitrary constraints are essential to any artistic endeavor. It's foundational to fostering creativity. So yes, it's an arbitrary constraint. That doesn't make it any less valid.