Walnut Ink Darkening Medium is great for adding an extra "punch" to Walnut Ink drawings.
Darkening Medium is a better choice than India Ink, which sacrifices Walnut Ink's unique watercolor characteristics and compromises the ability to lift colour or lighten areas. Because it is heavily pigmented and made using the same binder as Walnut Ink, Darkening Medium can be added to or mixed with Walnut Ink without changing the original working properties.
Although Darkening Medium can be used straight from the bottle, it is so heavily pigmented that it will behave more like a sumi ink by staining the paper and not lifting as easily as Walnut Ink.
This fadeproof, watersoluble darkening medium is acid-free and archival.