Who thought that HP´s low-volume cartridges No. 27 (black) and No. 28 (3-color) with 8ml of ink (quantity to be consumed by printing) would be the last scale of miniaturization of ink-jet cartridges, was wrong.
By introducing the No. 21 / No. 22 cartridges, HP re- duced again the usable ink amount by another 50%. Finally, if you compare this latest series of cartridges with the former HP No. 56 / 57 series, the ink to be consumed is been reduced by 71-74 %, down from 19ml (black) and 17ml (3-color) to 5ml each. The table above shows clearly how expensive the OEM inks have become compared by â‚¬ per ml. While the No. 57 has been already quite expensive with 2,05 Euro for one ml, with the No. 22 this amount has reached new heights: 3,40 Euro for one ml of ink - or: 3.400 Euro per litre!
For the HP No. 21 OCP recommends the black pigment ink BKP 49, while for the color cartridge No. 22 the three inks C 60 (cyan), Y 52 (yellow) and M 58 (magenta) are a perfect solution.
The cartridge´s design has changed in a way that refilling and remanufacturing of these cartridges is not possible by increasing the quantity of ink filled inside. Due to a much lower compression grade of the foam which is inside the No. 21 and No. 22 cartridges (compared to the No. 56 / 57), it is recommended to refill the color cartridge No. 22 just with max. 4ml per chamber to avoid leakage due to overfilling. Plesae bear in mind that with 12ml alltogether this cartridge seems to be "overfilled", but besides the 5ml (3 x 1,7ml) ink to be consumed the cartridges contains another 2ml of ink per color which still stays in the foam as it can´t be consumed. The black cartridge No. 21 should be containing max. 10ml after re-processing to avoid leakage.
Your OCP Sales team!