Varnish for Chalk Style Paint. Flat Out Flat Top Coat 473ml, is the perfect topcoat to seal the Chalk Style Paint by General Finishes. Instead of waxing, you simply apply this top coat. It is easy to use and gives a durable finish. It is also the perfect top coat for the Milk Paint and Gel Stain ranges to achieve a totally flat finish and add extra durability. If you prefer a low sheen you can choose the High Performance Top Coat in FLAT.