In testing printers and ink cartridges, we've rarely gotten unusable brand-name cartridges. But with most of the off-brand inks Consumer Reports tested for this report, we found plenty of variation in quality.

None of the cartridges we bought for the 2006 report leaked into their protective bags in the package, as they have in years past. Nevertheless, 7 of the 19 off-brand models we tested had at least one cartridge that was unusable--even after we ran the printer's cartridge-cleaning utility--because of clogging, or the due to the colors being extremely far off. A handful of Canon- and Epson-compatible products did not even fit correctly into their respective printers.

A handful of Canon- and Epson-compatible products did not even fit correctly into their respective printers. With HP-compatible cartridges, the printer's ink-monitor software utility did not work for the off-brand cartridges.

The bottom line. Keep spare cartridges on hand in case you get a dud, but make sure you use them before the expiration date.