Kuretake Clean Color Real Brushes have actual hair brush tips in a disposable form that will give you clean, water-based color on the go. The colors can be blended like watercolors in a palette when used with a water brush. Six colors available. Not refillable.
A gorgeous deep red brush pen with a hair tip that rivals refillable hair tip
brush pens. The line goes from thin to thick and back with ease, and can make
hairline strokes. Color stays strong and clear when used in conjunction with
other colors in the line. Not waterproof at all, so it will bleed across the
page profusely if even slightly touched with water. The big con is that it is
non-refillable, and that the colors available on Jetpens are limited.
Apparently there is a much wider range of colors in the line, including more
subtle colors than what are available on this website. I would be interested in
having these more subtle colors available, as these are far superior to the
Faber Castell brush pens (which do have a more subtle color range and waterproof
quality) in terms of durability.