Analysis of the Lincrusta revealed that a microscopic particulate had accumulated on its surface. The particulate was composed of particles measuring less than one micron in diameter. At this molecular level, the dirt actually forms hydrogen bonds with the metal salts present upon the painted surface of the Lincrusta. In effect, no amount of mechanical action or soap can clean away dirt that has bonded in this way. This photograph shows an area of the Smoking Room Lincrusta during cleaning. The bright square seen to the right in this photograph shows an area of Lincrusta after the grime has been removed.