The “Volcanic” glazes regroup different types of glazes like the so-called ”Drip” or the “Fat Lava”. The proper use of certain ingredients can cause more or less controlled gaseous reactions in the glaze, producing a characteristic texture on the object.
West German potters in the fifties were fond of this technique which was called “Fat Lava”. The look may sometimes seem rustic and crude but the variation in texture and color can also be very subtle and sophisticated as the work of Otto and Vivika Heino can illustrate.