Lichens are alive at harvest, but later they are simply stable organisms that maintain their structure, if they have an environment with a humidity between 40 and 60%. If the humidity drops below 35%, then there is a risk that lichens will become stiff, so brittle, and degrade.
They should never be positioned directly in the heat of the sun and also in dry areas, where humidity risks falling below 35%. It is also good that they are not positioned in tight spaces, because they can be detached by rubbing.
The reindeer moss wall does not require water, light or maintenance. It adapts to the surrounding humidity like a sponge.
A clean grease and dust free environment without excessive air movement is best.