What can you put over paint to make it smooth?

To achieve a smooth finish over paint, you can use a clear topcoat such as polyurethane, acrylic sealer, or varnish. These products not only enhance the paint's durability but also provide a smooth, glossy surface. For an even smoother application, consider using a foam roller or a high-quality brush to avoid brush strokes. Additionally, sanding the paint lightly with fine-grit sandpaper before applying the topcoat can further improve the smoothness.