Designed to produce cracking of emulsion paint. This acrylic medium creates dramatic two colour aged effects. The crackle glaze is applied over an emulsion base coat which will be the colour of the cracks. An emulsion top coat in the chosen colour is then applied over the glaze. The top coat cracks to reveal the base coat. You will need Polyvine Decorators Varnish to seal the base coat and also to be applied when effect is finished for protection.