Beware of which color goes in which hole! I'ts NOT the same for all brands of cartridges, not even for all HP catridges. BTW: Use a coctail stick or toothpick to locate and open the filling holes. That's a lot easier. Also, when taping of the holes, don't go outside the original sticker, or you may cover the essential little vent holes!
I'm buying ink from the same supplier for years, but I don't know what brand it is, because the supplier buys it in big quantities and they sell at 100ml or 500ml bottles rebranded with their logo. If you really want to be 100% certain you use the right ink you should buy the genuine HP GT53BK for black and GT52C, GT52M, GT52Y for colors. It's the ink that HP sells for the Ink Tank models which use similar printheads like these cartridges.
@lilybelle4117 Actually I buy from my local supplier because we have a contract and he gives me better price than online. But sure, you can buy them online. I can't recommend an online shop because I'm from Romania and I don't know the good ones in your country.
