Abstract. Let f be a transcendental entire function. We give conditions which imply that the Julia set and the escaping set of f have packing dimension 2. For example, this holds if there exists a positive constant c less than 1 such that the minimum modulus L(r, f ) and the maximum modulus M (r, f ) satisfy log L(r, f ) ≤ c log M (r, f ) for large r. The conditions are also satisfied if log M (2r, f ) ≥ d log M (r, f ) for some constant d greater than 1 and all large r.