Abstract: Electrochromic materials can be used in a multitude of fields to yield different effects. Importantly, a single chromatic variation may be used as communication means. Systems are described that use chromatic variations in culturally-meaningful ways.

Abstract: A bare diffractive microstructured area on a product is protected against wearing by one or more protruding elements. In an embodiment, the product is provided with a depression, whose bottom is further provided with a diffractive microstructured area. Thus, the rim areas of the depression form a protruding element with respect to the microstructured area. If the product is rubbed, for example, against the surface of a table, the protruding element prevents the rubbing surface from having a physical contact with the microstructured area. The microstructured area does not need to be protected with a transparent protective layer, which entails significant cost savings.

Abstract: A method for specifying products to be sold, in which a plurality of mutually substantially identical products and/or their packages are equipped each with an optical diffraction element of its own. The element gives the same visual impression in each product or its package. In addition to the product and/or its package, the material relating to the distribution or sales of the product is also equipped with an optical diffraction element giving the same visual impression as the optical diffraction element on the product or its package. The material may also be equipped with an element simulating this visual impression.