Kaweco Royal Blue is a washable ink for fountain pens. It could be easily washed out of the paper or erased with a special eraser. It also could be removed from clothes and different surfaces in case of any ink-related accidents.
Many brands offer royal blue inks. Kaweco's version, however, is slightly different — it has a barely noticeable purple undertone to it.
Kaweco Royal Blue dries pretty quick on most papers and has a good, moderate flow. It will work well in all fountain pens, new and vintage.
If you like this ink, you can get in as a 30ml bottle or as a pack of Standard International cartridges.