Taccia Inks have the perfect balance of permeability and viscosity so that it flows nicely on paper, but also is not harsh on the pen nibs. The pH value of the ink is neutral, so the ink is carefully formulated so that it does not damage pen resins or celluloid. These inks are rich with expressive power that you can fully enjoy fountain pen illustration with. Color: Ao (Blue) Water-soluble dye and aqueous ink Bottle: 40ml Glass Size: 60mm x 60mm x 56mm Weight: 5.8 oz (165g)