The cartridges perfect match to my Epson printer WF 3520. seats immediately fixed, are also recognized immediately. Black has twice the width and thus capacity and we also correctly displayed in the monitor. It is practically of no waste other than packaging. You have only a small plastic strip tear (ventilation ducts). You can not stain practically! The colors are indistinguishable for me only. Since each cartridge costs an average of just under 1, which is a truly a great alternative to the original cartridge.