I did not know that and so far, have not
used refilled cartridges in my HP7410 .. The
color seems to last a while, but I don't do that
much in color. My original (first) black is almost
empty. But it had a long life (about 1 year or so)
And HP does warranty their ink cartridges if they
do not work, especially if it is before the Use By Date.
So far, I have not had to try their warranty.