Weather-resistant steel in building is a paradox, aesthetically speaking. Its light-and-dark surface sheen has a warm coloration and a natural appearance. At the same time, it has a rough, puristic quality about it. These properties are based on a condition that is not usually regarded as attractive and that one normally seeks to avoid, namely rust. In the case of weather-resistant steel, however, the complete oxidization of the surface and the physical effects of this are quite different from undesired corrosion. In fact, the deliberate process of oxidization has a protective function. Although weather-resistant steel was associated in the past with constructional weakness and there have been examples of damage to buildings, today the material can be used quite safely. It is also economical, despite its slightly higher price, since no further corrosion protection is required. The absence of separate protective coatings also simplifies the disposal and recycling of the material. (Manfred Fischer)