How to refill the HP 21 black ink cartridge | en.Rellenado

How to refill the HP 21 black ink cartridge

I believe the ink cartridge hp 21 black is the most widely sold cartridge in America, this ink cartridge is one of the cartridges that has lasted the longest in hp printers, and the performance of this cartridge is excellent, it has about 5 ml of ink which allows for the printing of about 120 pages, after refilling the cartridges, the production is always reduced by 20% , this is normal , we know that it’s not the same , unless we put more ink than usual in our cartridge, but this would present a problem for the cartridge because this could cause the termination of its lifespan and then we would not be able to fill it again.

We always recommend knowing how much ink to refill your cartridges with, it does not matter which cartridges they are, they always have a limit for checking ink and this limit cannot be surpassed. We recommend reading how to know how much ink to refill your cartridge with, this way we avoid making mistakes and damaging our cartridges.

Instructions on how to refill the hp 21 black ink cartridge

Before starting, we recommend cleaning the print connectors for this type of cartridge, it is necessary but not mandatory to do this since these cartridges perform well, but mainly if you have not used them for a long time it’s possible that they have dry ink in the heads which is not good, we recommend reading how to run a print head cleaning cycle for my cartridge.

After completing the cleaning cycle, remember that it’s not mandatory, but just in case you do want to do it, it is recommended after three refills. Let’s proceed to the refill procedure.

Step 1.
Place the cartridge in a place where ink spills are allowed, a white material is not recommended as ink cannot be removed from it, instead we would recommend a black material, even a flat surface where ink can be removed with ease would work.

Step 2.
We now proceed to removing the label that has the cartridge number on top, we always recommend removing the label from the cartridge before refilling it, this allows the required amount of air to enter so that the printing is of the highest quality and optimal performance due to this cartridge. Slowly remove the label to avoid damaging it.
Cartridge orifice
Point of entry
Step 3
Now we slowly refill with 5ml of ink, please do it very SLOWLY , you need to do it in this way so that the ink inside the cartridge may spread in the best way and fill the whole sponge.

Step 4
Now that we have filled the ink cartridge, all we have to do is print a test page with this cartridge, we recommend leaving the cartridge in the printer.

Even if you have followed this procedure, it is possible that it will not print out very well, if so, you are asked to please contact us through a comment on this post and we will help you immediately.



  1. Hello sir
    I try to refill the hp21 cartridge .but still the print head is not working. Resolve the problem

    1. Hello you can fix you problem with the next process:

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