How do I know when an ink cartridge needs to be replaced?

• The printer's indicator lights will inform you when it is time to obtain a replacement ink cartridge and when it is time to replace an empty cartridge. To find out which ink cartridge is empty, check EPSON Status Monitor 3 (for Windows 98, 95, 2000, and NT 4.0) or EPSON StatusMonitor (for Macintosh). You can also tell which cartridge is empty by checking the speed at which the error light flashes when the print head moves to the ink cartridge replacement position. Replace the black ink cartridge if the error light flashes at the same speed as the power light. Replace the color ink cartridge if the error light flashes at twice the speed of the power light. Replace both the black and the color ink cartridges if this light remains on.