Winsor & Newton watercolor expertise in a marker! These markers deliver precision and control and are compatible with all Winsor & Newton watercolors and mediums. Their lightfast formulation offers optimal performance, transparency and brightness. Each twin-tip marker has a flexible brush tip on one end and a fine point tip on the other end. Once a drawing is made with markers, it can then be transformed into a watercolor painting by applying water with a brush. The sooner water is applied, the better the resulting washes will be. Colors can be mixed either on the paper or on a palette. Each marker contains 3ml of ink. The 6-color set consists of cadmium yellow hue, alizarin crimson hue, Prussian blue hue, sap green, yellow ochre and ivory black. The 12-color set consists of lemon yellow hue, cadmium yellow hue, cadmium red hue, alizarin crimson hue, dioxazine violet, cerulean blue hue, Prussian blue hue, Hooker''''''''s green dark, sap green, yellow ochre, burnt umber and ivory black.