Set includes one brush pen and three black water-based dye ink refill cartridges. The famous Kuretake brush pens have fine nylon bristles perfect for creating strokes ranging from broad to super thin. Artists and calligraphers love Japanese brush pens because of their portability, convenience, and high quality. Ink cartridge refills and brush head replacements are available. The brush should optimally be used once a month, but if it dries, you can soak the tip in room temperature water overnight. Refill with a new cartridge after soaking. Bristles are smooth and springy. Extremely practical and controlable with a great snap-back of the hairs. Ideal for Inktober participants. Kuretake's famous fountain brush pen - a quality brush pen that is refilled with cartridges or from bottled ink via an optional converter. The No.13 has a fine synthetic tip able to create a wide range of lines, for all purposes including sketching and lettering. 3 dye-based black ink cartridges are provided. Use Platinum Ink Cartridges to refill. Kuretake Fountain Brush Pens are compatible with the Platinum Fountain Pen Converter, for use with bottled ink. Supplied boxed with 3 refill cartridges.