HP printer cartridges contain a print head on the floor and be topped by peeling back the sticker and injecting ink into the center of the cartridge. Penetrate into the sponges in the HP printer cartridges with the help of an employee of an ink-filling station in this free video on HP Printer Cartridges. Expert: Bio Taylor: Taylor has five years experience refilling ink cartridges at a gas station. The gas station offers new and refurbished ink cartridges filled at a reduced price. Filmmaker: Michael Burton