This can happen if too much paint is applied at once, or if additional coats are applied before the initial layer has dried. Remember that whatever the surface texture is in the painted stage will carry over when you electroform.If you are using my alcohol based paint, then you can soften the cracks by dipping your paintbrush in the thinner (90%+ isopropyl alcohol). You may need to do this a few times. Once smoothed out, you can repaint the area with conductive paint to ensure the paint thinner didn't obstruct the conductivity of the surface.