The dry brushing process involves removing most the paint from the brush so that it can be brushed over a surface and only the most raised areas will catch the paint, accentuating the texture on the piece. In oder to see how "dry" the brush is, it's best to test it on textured surface that is not the piece you are working on. This can also be used to remove the amount of paint on it until it's appropriate for the task at hand.
This dry brush Palette has 4 texture areas to run your brush along to get it perfect for dry brushing. Additionally, it has a palette section at the bottom to put a small amount of paint on to work with. This is perfect if you regularly use a wet pallet, which is not ideal for use when dry brushing.