Black ink has spaces in lines, color prints fine.

Generally, you will need to run the nozzle cleaning routine several times. Compare the previous block print with the current one after nozzle cleaning to see if it is improving. This is a problem with ink jet printers, the ink dries on the nozzle and makes gaps.

One other place to check is the contacts between the cartridge and the cartridge carrier, a little bit of dried in will break contact. This can be cleaned with a damp lint free cloth or use a cotton swab, do not use paper towel because it can leave paper fibers that will stick to places hard to clean.

Here is a link to one seller who has a cleaner kit: http://www.ebay.com/itm/Epson-Stylus-NX4.... There are other resources, this is an example. I haven't tried cleaning the print head on this model, I do not have an opinion for this seller and recommend doing research to make sure this is what you can use for the cartridge/print head problem.

I don’t know if this is what you are talking about but my inkjet printer, when it prints a jet black square, you can see the bands how they separate from each other as opposed to just one large flat square of black…. Is there anyway to fix this?