The HP 731 DesignJet Printhead and Original HP Bright Office Inks are designed and tested together to produce bright color and bold image quality for technical prints on plain papers..Ink drop: 6 pl.Cyan, magenta, yellow, gray, photo black, matte black (2 colors per printhead).Ink types: Dye-based (cyan, magenta, yellow, gray, photo black); pigment-based (matte black)