Dr. Ph. Martin's Radiant Concentrated Watercolors are brilliant, concentrated, dye based watercolors that can be applied with Brush, Pen, or Airbrush. Dr. Ph. Martin's Radiant Concentrated Watercolors are NOT lightfast and are not waterproof. They are intended for work that is to be reproduced. The colors will fade from sunlight or fluorescent light (ultra-violet) however, they will not fade in a portfolio, or under incandescent light. protect from fading with ultra-violet absorbing glass, plexiglass or UVA acetate. You can make them permanent on fabric (textile) silk, cotton, batik, tie dye when used with additives as follows: salt and vinegar, alum, or soda ash (calcium carbonate). Make a test piece first to make sure of the washfastness of the dye on fabric. For lightfast archival watercolor we recommend you use Dr. Martins Hydrus Fine Art Liquid Pigment Watercolors.