Universal critical amplitudes in finite-size scaling

It is argued that there is no nonuniversal, system-dependent, multiplicative metric factor in the finite-size scaling relation for the singular part of the free energy near a bulk critical point. New universality properties for various critical-point amplitudes follow: one universal ratio is $\frac{L}{{\xi }_{\parallel }\left(T_c\right)}$ in finite-size transfer-matrix calculations.