Abstract: Primer systems foe silicone elastomers bonded to glass or plastic substrates, particularly those elastomers used as interlayer materials in a transparent lamination of such substrates, are described. The primer system consists of a thin layer of a silica-based adhesion promoter which is applied directly to at least one surface of the substrate. An organosilane primer containing (i) silanol or functional groups that can hydrolyzed to silanol, and (ii) polymerizable alkene or silicon hydride functional groups, or preferably both, is applied over the silica-based adhesion promoter layer. Alternatively, the silicone elastomer may also contain silanol groups or functional groups that can be hydrolyzed to silanol, and polymerizable alkene or silicon hydride functional groups, thereby making a separate primer layer unnecessary. Both components must be present for the primer system to provide a more durable adhesive bond.