ink (medium)
A medium that consists of ink which has been applied to a surface, typically paper. The ink can be applied using different tools, such as a nib pen, ballpoint pen, technical pen, marker, or brush, or through the printmaking process. Ink is commonly black, but can be blue, as in the case of some ballpoint pens, or come in many colors. Depending on the method used, ink can appear as lines of constant or varying width, or in large swatches.