I have the cartridge even properly a few days in an Epson C86 in use and it works right from the start. The cartridge is transparent on one side. As you can see that the cartridge is completely filled. So it does not contain Fils- block as with other cartridges. During the printing process, the ink is always well mixed. To function on prolonged continuous use, I can not say anything yet, but I will gegf. grudge.