They [Roland] might only stand behind them for two years, but about a year ago, I found an old set CMYK of 220's, from when we first bought the machine, back in 2006. At first we were afraid to use them, but being the penny-pincher I am, we used them as needed and they worked fine after almost 6 years of sitting in a drawer. We shook them up real good, then let them settle for a few days before putting them in.