Refilling the HP 21, 21XL, 27, 56 black ink cartridges at home is very easy and can offer you great results, with very little equipment. All you need is one syringe, plus some universal . Simply remove the label, widen the fill holes (if necessary) and fill the relevant chambers of the Hewlett Packard ink cartridge with the amount of ink mentioned below.
For these cartridges, we recommend injecting the following amount of black ink into the hole closest to the printhead:
HP 21/C9351AE: 5ml
HP 21XL/C9351CE: 12ml
HP 27/C8727AN: 12ml
HP 56/C6656AE: 12ml
We recommend sticking to the lower fill for the HP 21 as these cartridges have a smaller sponge and are physically restricted inside the cartridge. As such, over filling them can result in ink spilling inside your printer.
This guide is intended purely to show where to inject the ink into these cartridges and how much we recommend using. For full refill instructions for these cartridges, please click here.
HP 21, 21XL, 27 and 56 Refill Video Guide
Compatibility
These cartridges are compatible with a variety of HP printers, including:
HP PSC 1410, 1400, 1401, 1402, 1408, 1415 and 1417
HP DeskJet 3320, 3325, 3420, 3425, 3500, 3520, 3535,
3550, 3600, 3620, 3645, 3647, 3650, 3651, 3653, 3740, 3745, 3810, 3816, 3840, 3843, 3845, 3847, 3900, 3910, 3920, 3930, 3940, 450, 450CI, 5150, 5151, 5160, 5168, 5510, 5550, 5551, 5552, 5600, 5650, 5652, 5655, 9670, 9680, D1311, D1320, D1330, D1341, D1360, D1368, D1400, D1420, D1430, D1445, D1455, D1460, D1470, D1500, D1520, D1530, D1560, D2300, D2320, D2330, D2345, D2360, D2368, D2400, D2430, D2445, D2460, D2468, F2100, F2110, F2120, F2128, F2140, F2149, F2180, F2185, F2187, F2188, F2200, F2280, F2290, F300, F310, F325, F335, F340, F350, F370, F378, F380, F385, F388, F390, F394, F4100, F4172, F4175, F4180, F4188, F4190 and F4194.
HP Officejet 2110, 4300, 4312, 4314, 4315, 4317, 4319, 4355, 6100, 6110, 6127, 6612 and J3680.
