The phase composition, microstructure, porosity, density and consistency of positive plate pastes prepared at 35 and 80° C were determined as functions of the amount of H₂SO₄. It was found that the phase composition of the paste is determined by the H₂SO₄ oxidized lead powder ratio and by the temperature at which the paste is mixed. The paste density is determined by the liquid powder ratio. The total pore volume is controlled by the paste density while the average pore radius and the consistency are determined by the phase composition. Stoichiometric calculations were made for the phase composition of the pastes. It is concluded that the paste represents a non-equilibrium system consisting of crystalline basic lead sulphates and oxides and amorphous sulphate-containing components.