Compatible Ink for Epson

Hi all, so I use compatible inks for my Epson 7800, 7880, 7890, and 7900. I buy it in by the litre from someone local to me. It's always been fine, though I have some problems with black when it is full black which may be the ink or may be the paper (I've opened a thread for this).

The thing is I don't really know how to know if this is good ink or bad ink. I buy the same ink which I'm advised will work on all of the printers, though as far as I am aware there is some variation between the genuine ink for the 7800 & 7880, and the 7890 & 7900.

I was thinking about getting in some genuine cartridges and creating profiles with each so I could see the difference but it's pretty pricey buying in the genuine carts. Before I invest does anybody have any ideas, suggestions, or recommended reading about understanding compatible inks?

 

You can use refillable cartridge for your printers, the ink for your epson 7800,7880,7890,7900 are not same, maybe you can clearn printer head.
we produce many large format printer consumables,most of our customers chose refillable cartridge and use compatible ink,I don't know your
problem solved it nor not,you can add my skype: outac-ciss ,see if i can give you some support.