Noodler’s Kung Te-cheng is one of the closest inks to a true blurple. It is right between blue and purple. Indigo would be a good description. It is a bulletproof ink and resistant to water, solvents, UV light, bleach, and lasers.
This ink is offered in a 3oz. bottle.
Noodler’s Inks are produced in the USA and made to the highest of standards.