Since I wasn't in the same town as most of my letter writers, I couldn't afford to mail 3-rings, but I did make folders with addressed envelopes (stamped for the non-academics), my resume and personal statement, and this handy sheet I got from SCCO listing clinical and didactic qualifications for optometry students that gave a pretty good idea of what all schools were looking for. All my letters were received by the schools within 3 weeks of me sending my folders out, so it was definitely worth the little extra effort.