conservation image Wall Paintings at Mogao Grottoes
 

Detail of exfoliation of painted surface on the north wall (exfoliation is characterized by the lifting and resulting loss of paint, ground, and upper plaster layers). This phenomenon caused by cycles of deliquescence and recrystallization of soluble salts is particularly severe in areas previously treated in the 1970s with synthetic and impermeable fixatives. Photo: Neville Agnew.