The LINRA Sunray Crease-evaluator is a photoelectric instrument for measuring the creases retained in a fabric subjected to the LINRA Sunray test. The result is expressed as the equivalent angle of the crease in a matt surface that would have the same appearance as the specimen when viewed from above and illuminated by light at an angle of 20° to the horizontal. This equivalent angle of a matt surface is virtually the same as the actual angle for most fabrics.