Electrophoretic deposition of luminescent materials such as has been accomplished by the adsorption of inorganic cations of Mg++, Ca++, Ba++, Sr++, Al+++, Na+ , K+ , Li+ or +, from nitrates, chlorides, and bromides, in polar liquids such as isopropyl alcohol with a critical concentration of about 1% . An explanation of the adsorption charging and the pertinent factors which effect cataphoretic deposition for a calcium magnesium silicate‐magnesium nitrate system is presented. Acetone has been found to have a beneficial depolarizing effect, while magnesium salts produce a cementing action on the deposited phosphor layer.