I153. Ecoline Liquid Watercolor. 30ml (1oz), dropper bottle.
A free-flowing ink in a wonderful selection of very vibrant colors, which are transparent (except Black) and non-waterproof. The colors mix well and allow for beautiful gradients. Used primarily for pen, brush, and airbrush. But especially popular for folded and ruling pens. Works well in the Osprey Zebra G Titanium Fountain Pen and Pilot Parallel Pens, use in other fountain pens with care. See drop down menu for available colors! Recommended by Thomas Hoyer, Kei Haniya, and numerous other calligraphers.
If you're looking to add some vibrant color to you watercolors, these are it. They can provide a great base layer for you to paint on top of. They maintain color quite well, and work well with metallic paints/inks.