Book excerpt: Woven Optical Illusions explores a variety of optical effects through the medium of weaving. Suitable for weavers of all experience levels, it explains the basic principles behind the illusions and shows how to create the effects in selected weave structures to give a wide range of examples and possibilities. Projects are taken from concept through weave design and development to a woven result. With over 500 illustrations, including detailed drafts and images, this fascinating book is designed to whet the appetite of anyone who is interested in optical play. Includes Clear step-by-step explanations of the complete design process and describes the science behind the optical effects and some of the history of their discoveries. It also incorporates inspirational images from other weavers working in optical effects and projects range from plain weave through to advancing twills, featuring tied weaves such as summer and winter, taqueté and beiderwand, double cloth, colour-and-weave, shadow weave, and deflected double weave.