Wrinkles, Creases and Folds (image) Brown University Share Print E-Mail Caption With increased compression, a flat surface with a stiffness boundary layer (a) can become a wrinkle (b) and then a fold (c). Other possibilities include an instantaneous crease (d), a wrinkle-crease (e) or a fold-crease (f). Credit Kim lab / Brown University Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.