If there is enough clearance in the Epson printer to do what many of us have done with Canon carts - buy some phillips slot stainless steel pan head sheet metal screws slightly thicker than the fill hole in the MIS carts and the shortest length you can find. Buy o-rings that fit really tightly on these screws to use as a seal. Screw them into the fill hole. They are self tapping and cut their own threads. When you tighten them down be careful not to overdo it as you will squeeze the o-ring out of place and lose the seal. Doing this will also make the fill hole slightly larger so filling will be easier.
I have a set of MIS virgin carts for my Canon printers and they work just fine. I agree that the little plastic plugs are impossible, so I did the screw/o-ring thing.
I have a set of MIS virgin carts for my Canon printers and they work just fine. I agree that the little plastic plugs are impossible, so I did the screw/o-ring thing.