Do you have an Epson MK cartridge/chip? If so, you can remove the chip and attach it to the 4880 MK refill cart for your printer to see it as MK.
The x880 refill chips are programmed with all color channel info, so they can be installed in any slot. This works fine with the color positions, but I have found the PK code seems to be stronger than the MK code, and occasionally the printer can get confused with the chip programming when in MK mode. To get around this, you can keep your printer in PK mode (and just select the appropriate ICC profile and media setting for the paper you're using), or attach an Epson MK chip to the MK refill cart for the printer to read it as only MK. Due to the x880 refill chips being programmed with all color channel info, the Epson print driver will display all (both matte and gloss) Media Type settings no matter which black refill cart is installed- so you can have MK ink installed, but be able to select glossy media settings if you'd like- and vice versa. If you wish to attach an Epson 4880 MK chip to your refill MK cart, I have included instructions for doing this below.
Attach Epson chips to refill cartridges:
Looking at the chip on the Epson cartridge, you will notice there are two small plastic points that hold the chip in place. Make a note as to which way the chip fits onto the cartridge so you can attach it to the refill cartridge in the same direction. Using a straight razor blade at an angle carefully cut the top of these two points off, which will release the chip so you can carefully pry it off the cartridge using the edge of the blade. You can also use a sharp knife or something similar to pry the chip off the refill cartridge. You will notice the same two points on the refill cartridge where the chip goes (pry the chip off the refill cartridge before attaching the Epson chip in it’s place)- gently line up the Epson chip with these points and attach it to the refill cartridge by using an adhesive such as double sided tape. Making sure your hands are nice and clean, press the chip to make sure it is tightly seated and flat on the cartridge. Now, using the chip resetter- reset the chip and insert the cartridge into your printer.
I hope this helps, please let me know if you have further questions or there's anything else I can help you with.
Best regards~ Dana