Summary: Before my order from ink4art.com, I had used one set of original Epson ink and two cartridge sets of generic ink from 123inkjets.com in my C80 printer. I was happy with them, though the printhead tended to dry with the replacement ink a little sooner.
Then I was attracted by a 'deal', 3 sets (12 cartridges) of ink for $38, from ink4art.com. As the old ink ran out, I put in the ink4art cartridges, and the printer quickly met its fate. The black cartridge was leaking, and soon enough black ink was everywhere in puddles in the printer and in big stains on the paper. The yellow didn't work from the next day (either the excess black clogged the yellow nozzle or the yellow cartridge was altogether defective), while the magenta lasted 2-3 more days.
I read newsgroups and tried from mild to more and more aggressive washing/unclogging techniques (clean nozzle cycles -> soaking -> syringe with warm water). All in vain.
Now I am down with $150 (printer price) + $38 ("deal" value). ink4art customer service replied my first mail, and offered store credit. I respect that, but further quantities of crap ink was entirely useless. They did not reply my second mail, though I was always polite.
Learn from this and avoid ink4art. Avoid Epson too, according to web stories other printers are less prone to clogging problems. | 
