We review Wilson's original derivation of his recursion formula for the renormalization group transformation of the Ginzberg-Landau model. His hierarchical approximation was combined with the use of wavelets that were not known to exist at the time. We identify the wavelets as Sobolev wavelets that have been constructed since then and refine the recursion formula by using information that is now avaialble on the wavelets. Wilson's ultraviolet cutoff is replaced by a wavelet cutoff, which is canonically related to the lattice RG transformation. © 1994 Academic Press, Inc.