By printing single-loop mirror-symmetrical split-ring resonators on high-permittivity substrates, a type of negative index material was realized with less usage of metals and broader negative-index bandwidth than conventional negative index materials. The underlying mechanisms of realizing negative permittivity by means of high-permittivity substrates and of double-negative pass-band were analyzed. The influening factors on the double-negative pass-band were analyzed both numerically and experimentally. By experiments, the proposed method of realizing double-negative property was verified. Both the theoretical and experimental results show that broad double-negative pass-band can be realized using the proposed method.