Inkjet printer having nozzle capping mechanism and ink priming method using the nozzle capping mechanism

An inkjet printer structure having an improved capping mechanism to smoothly fill inks from ink packs into empty flow channels, and a method of ink priming. The method of ink priming includes mounting a cartridge in which flow channels connected to nozzles are empty on an inkjet printer main body, mounting ink packs to be connected to the flow channels in the cartridge, blocking the nozzles by moving up a cap having sealing protrusions to the cartridge, circulating inks in the ink packs through the flow channels by operating an ink circulation pump for a predetermined time while the nozzles are blocked by the sealing protrusions, and separating the sealing protrusions from the nozzles after the predetermined time elapses.