This product is a clear medium that is applied over acrylic paint to achieve the look of aged paint. A basecoat of acrylic paint is applied onto the surface area. An even coat of Crackle Medium is brushed on and left to air dry until tacky to the touch. With a contrasting colour of acrylic paint a topcoat is applied with even, linear strokes (cracks will follow the direction of these brush strokes). The topcoat will begin to crack within minutes as the crackle begins to dry.