The symmetry concerning the fabric pattern is not always suitable for the quality that we expected from fabric textile. The moire effects produced by a periodic structure may be caused by various and diverse factors as folds, lines, etc. The defect that we are concern is bright and dark fringes appearing in the Nylon Fabric are viewed with necked eye, from a particular angle using white light. To prevent these annoying effects, one should be focusing the research basically on geometrical fabric structure, physical, optical and dyeing.
We start this work by an exhaustive study made to obtain enough information in order to identify and analyze the problem in order to identify, explain and prevent it appearance. To realize that we may define the factors that causes the phenomena. Concerning the experimental results, we begin with a conventional experiment called "Flat table examination" using Fluorescent white light bulb as types of illumination. We have used as well a microscope examination. It is useful to inspect the fiber and yarns which may have different characteristics of size and form. The light interaction with the fiber will produce especially kind of reflection and absorption.
We finish the work by designing and developing an optical system able not only for detecting those kinds of fringes. As well to allow some defects inspection. We believe that some measurements are necessary during some process of fabrication (dyeing, spinning and knitting), at least to reduce this types of defects.