Abstract: The present invention provides improved methods for conducting living/controlled polymerization on polymeric solid supports. The improved methods allow polymerization to occur directly from the non-functionalized surface of a bulk support. In addition, polymerization may be re-initiated to provide co-polymers. The disclosed methods may employ the non-nitroxide-based RAFT and ATRP control agents that allow controlled polymerization to proceed at relatively low temperatures (<80° C.). Furthermore, these improved methods may provide graft polymers with decreased levels of “in-growth” of the bulk solid support. The invention also provides substrate polymers, with improved properties for solid phase synthesis and diagnostic applications, which may be made by the disclosed methods.