To install your HP Envy 7858 ink cartridge(s), draw out the ink cartridge access door. Once the carriage is quiet and inactive, proceed further. Unpack the ink cartridges. Hold the ink cartridges only by the black plastic on the ink cartridge. Take the plastic tape from the ink cartridge.
Insert the new ink cartridge at a somewhat upward angle into its designated slot, and then carefully force up on the ink cartridge until it locks into position.
Repeat this procedure for the other ink cartridges. Shut the ink cartridge access door.
It uses HP Thermal InkJet technology. It operates with 2 cartridges. It is compatible with HP 64 and 64 XL. It lets you get 2X more pages with Original HP Ink against refills. The HP 64 XL can produce about 415 pages.
It supports HP Instant Ink. The HP Instant Ink plan, you pay a monthly fee to print a defined number of page per month. The plans take into account on the number of pages you 123.hp.com/envy7858 print and not on the number of ink cartridges.