These medium tip brush pens are from Kuretake and are part of the Cambio Tambien Collection. This Brush Pen Set 6VA includes the colors Red, Cadmium Orange, Cadmium Yellow, Burnt Sienna, Viridian, and Ultramarine. These pens are easy to use for writing and coloring. They are great for painting, artwork, brush lettering, and illustrating. This is a water-based pigment ink that is water-resistant when dry, lightfast, odorless, and xylene free. These pens produce smooth lines without needing to adjust the ink flow. These pens are refillable.