These inks are part of the Keystone Formula fountain pen ink line, our traditional dye-colorant ink. The 100mL volume will provide approximately 125 standard converter refills assuming a 0.8mL draw.
Birmingham compartmentalized their fountain pen ink recipes into four principal categories characterized by differentiating elements of the colorant component in the formula. A colorant is a dye or pigment that exhibits color. An ink vehicle is a series of chemicals used to transport colorant from storage reservoir to substrate (paper).
Keystone Formula inks are engineered using water-soluble dyes to produce a broad spectrum of colors with a variety of unique and desirable writing properties. Fitting the bill for a traditional fountain pen ink, this series by far the most popular.
