Evaporative Poster:This 3-dimensional surface releases moisture into a lot of air. The open surface prevents mold growth. Compare, a sliced apple dries in the fresh air, but when wrapped in, it starts to mold. Evaporative posters are designed as wearing parts, since the cleaning of such elements would be difficult and costly. Clean evaporation is guaranteed. Water adds with the amount that evaporates such substances as lime, minerals, metals, etc. to the poster. These will cause discoloration of the poster. They are of natural origin and harmless. The color “metal” is very clear and can-not cover the discoloration. Include colorful Panels if this influence is disturbing you.