John has been with the BOS since it was first formed in 1967 and has given years of invaluable service as our chairman. He continues to study paper-folding from a theoretical standpoint, producing many informative and thought-provoking essays. He developed a mathematical way of describing folds (OIL, the Origami Instruction Language) and also "Pureland", which requires a model to be folded using only valley or mountain creases