How can time and process be represented in the interior through wear and tear? An exterior space is exposed to weathering.  An interior space is exposed to movements of bodies and object, mechanical and repetitive use. 
Layers of paint are added on top of each other in an additive process. A subtractive process then occurs when people use it. The paint molecules fall off and travel elsewhere.
The same method could be applied to other surfaces, for example a tabletop.