One of my personal preferences for pattern work is manila folders...they're a nice mix of stiffness and flexibility that allows me to essentially prototype a piece with the folders by making rough cuts, using tape for the seams, making fine-tuning cuts, then simply removing the tape and unfolding for the pattern.
My laser-cutter-owning friend and I do this for both my leather and his acrylic, testing patterns on the outrageously cheap folders before attempting them on the more expensive mediums. In fact, we now refer to them as "prototyping sheets," simply because both of us felt like using a laser cutter on manila folders sounded like overkill...
