You can easily add texture to your silk painting by adding salt while your piece is still wet. The salt is a drying agent and will actually pull the dye toward it. You can buy salt specifically for silk painting and you can also experiment with kosher, rock or even table salt for effect. It will pull color out of your piece creating darker and lighter sections or it will mix an area where you have two colors coming together.
Salt technique by Mary Kaye O'Neill
Salt technique at Beatriz Castro's workshop.
Salt technique on charmeuse, by Gloria Lanza Bajo
Salt technique by Mitzi Ash
Salt technique by Connie Simonsen