Information contributed by Expert Bob_HeadrickĮxplanation in Thread Question regarding Photosmart 7525 / Photosmart 7520 – five ink cartridges Explanation document (also linked in the text below) about how ink is used: Ink Usage in Inkjet Printersīob explains the use for the regular black 564 and the photo black 564 ink cartridges used in the Photosmart 7520 and the Photosmart 7525 printers.Select Paper type Plain Paper to use Black ink (as opposed to Photo Black).Photo Black and Regular Black are not the same thing and are not interchangeable.