The ES37 Water Brush Pen Series features an innovative design with a built-in water reservoir tube, eliminating the hassle of traditional watercolor brush cleaning and making water buckets a thing of the past. The brush is made with soft, durable nylon fibers and is available in various brush sizes as well as flat-tip options. Portable, easy to clean, and offering precise water control, it allows artists to moisten the tip simply by gently squeezing the barrel—perfect for washes, blending, gradients, and shading effects. Cleaning is just as simple: squeeze the barrel and wipe with tissue to remove pigment from the bristles. Ideal for outdoor sketching and travel use, it works seamlessly with water-based colored pencils, markers, watercolors, inks, and other media to support a wide range of creative applications.