Invisible ink for inkjet printers that use "micro Piezo" printhead please ask us about compatibility before you purchase this item. Fill the ink into the cartridges as follows : WHITE ink -> Black ink cartridge CYAN ink -> Cyan ink cartridge LIGHT CYAN ink ->Light cyan cartridge MAGENTA ink -> Magenta ink cartridge LIGHT MAGENTA ink -> Light magenta ink cartridge YELLOW ink->Yellow ink cartridge Absolutely invisible under natural light, prints made with this ink become visible under any UV (ultra-violet) light. For best results use non fluorescent printing paper. Full list of instructions is included. This price it`s for 6 x 10 ml Invisible UV ink bottles(white, cyan, magenta, yellow, light cyan ans light magenta).