The problem of the protection of stained glass against water-initiated chemical corrosion. Organic polymers and inorganically modified polymers are currently used, but have limited service life and durability. The authors suggests that oxide coating would offer much greater resistance to water penetration, since its permeability is ten times less than that of an organic coating. Oxide coatings also have greater scratch resistance. Compares the performances of different oxide and non-oxide coatings and presents methods such as sol-gel processing and vapour deposition, which could be used for low-temperature application. Tables, diagrams, 14 references.