Dr. PH. Martin’s Synchromatic® Transparent Water Color colors are easy to handle and are very transparent. They can be used in airbrushes. They are designed for work that requires transparency, such as retouching and hand coloring photographic papers and films. They are used in Paul Wiessmeyers violin retouch workshop. Each color comes in a 0.5 oz (15 ml) glass bottle with its own eyedropper. Like all aniline dye based colors that are fugitive when exposed to direct sunlight over time.