A liquid composition for forming an activator-containing layer on a substrate, for activating a chemical reaction to produce a solid layer on the substrate, comprises activator, surfactant and solvent and/or binder. The liquid composition is deposited on a surface of a substrate, desirably by inkjet printing. The layer is used to activate a chemical reaction to produce a solid layer on the substrate surface, e.g. a layer of conductive metal. The surfactant in the liquid composition has beneficial effects on the behavior of the liquid composition when applied to certain substrates.