Traditional pathologies
Flexible floor coverings

This phenomenon, also known as moiréing or shading, is a classic of its kind. It affects the carpet's pile and gives the impression that the carpet is stained or has been stained: large halos appear on the carpet's wear layer, provoking legitimate displeasure on the part of the user. This can often be seen – and is very easy to spot – on doormats made from plant fibers.

This is in fact an optical manifestation that is the consequence of the couchant that velvet takes on when used. Light is not captured in the same way by differently oriented sunset areas. If you place a mirror on the carpet, you'll notice that dark spots on a light carpet become light on a dark background when reflected in the mirror...

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