through the crackle. after it dries, paint a coat of elmer’s glue on the surface: thin for light crackling, thick for heavier and bigger cracks (apparently the new extra-strength glue is not as good for this as the old formula but it worked for me). let the glue dry so some of the surface looks flat rather than shiny and it feels sticky, not wet (i used a hair dryer to speed the process). next paint on a thin or thick layer of your next color, right on top of the glue. when this layer and the rest of the glue dries, it will crack and show the other color 