I88. Winsor & Newton Iridescent Medium. 2.5oz, plastic bottle with screw top.
Iridescent Medium An easy way to add some sparkle to your projects. Mix with wet gouache or watercolor or apply on dried watercolor areas to produce an iridescent effect. Easily diluted with water. This product can also be added to various inks to create a custom iridescent color (does not work with Ziller). Gum Arabic binder.