Abstract: A phosphor layer for an electroluminescent panel comprises a phosphor powder held in a binder. The binder comprises a mixture of two constituents, one of which is a drying oil or a semi-drying oil or a derivative and the other constituent is a sol-gel precursers. Examples of suitable oils are linseed oil, rape seed oil, sunflower oil and soyabean oil. Examples of suitable sol-gel precursers are tetraethyl orthosilicate, boron iso-propoxide, aluminium sec-butoxide and titanium iso-propoxide. Metal salts such as metal alkoxides, metal acetates and metal nitrates may be mixed with the sol-gel precursers.