With apologies for barging in late in a thread that might not have a lot of remaining interest, & purely FWIW of course...
Over the last 15 years or so I've found that OEM ink cartridges, besides being vastly over-priced, tend to have something added [glycol?] to keep them & the heads from drying out as rapidly as non-OEM inks. Aftermarket inks may also come very close but not exactly match OEM colors -- something more noticeable with 6 color printers.
Generally refilling is better quality than buying so-called re-man cartridges -- re-man often being more to get around legal fine points than actually meaning reman or refurbished... cartridges with the head [e.g. some Canon] may be an exception, but as the Canon cartridges at least only recently appeared at significant savings over OEM, I haven't had a chance to try them. The reason I say refilling is better is non-OEM casings may leak, may not fit properly, & you have no control or way to judge the amount of ink they hold -- I have gotten some that probably were at best 1/2 full. Epson is a special case because of the electronic version of DRM added -- if you print enough to justify it there are aftermarket cartridges designed to be both resettable & refillable, but the initial investment can run as much as a new set of OEM ink at some place like Sams Club [often cheapest].
The main limitation of refilling is the old ink dried on the sponges inside, reducing capacity unless you clean them out. With cartridge/head combos like many Canon's you can also get clogged heads from sitting [empty or full] prior to (re)use, which can take a day or three to dissolve -- I usually run a couple of cleaning cycles, let it sit, print a test in notepad to reset, then run a couple more, with a 12 hour or overnight rest to soak... running the 3rd cleaning cycle without a real print job in between often triggers a Super cleaning cycle that wastes a lot of ink, makes a mess inside the printer etc.
Personally my problem is no one prints enough so heads clog, OEM ink or not, & family members have been un-willing to use a printer in another room over the network, so I've got 3 to deal with. My solution is to buy cheap refurb printers on sale -- I've bought 1 Epson & 6 Canon AIOs over the past 3 or 4 years, paying between $15 & $35 each, which in all cases was less than the new OEM cartridges that came with them -- I generally prefer the Canons using 2 cartridges that each include the heads in case one gets thoroughly clogged... permanent heads can both clog & do things like leak, which I have seen in the past from Canon. When a cartridge needs replaced I'll pull the top of the old one, soak everything to clean it, then put it back together, sticking it on the shelf until needed, when I'll refill it. Working that way I can use each cartridge 3 or 4 times usually.
I was able to buy the Epson cheap because it was a problem model [RX 595], & I originally intended to get rid of it when the cartridges emptied... instead I held onto it because it prints DVDs. It has a habit of rejecting/not recognizing cartridges (OEM or not), the aftermarket ones from meritline are the only ones I've had luck with, & frankly I would have been better off to buy an OEM set at Sams Club had I known how much I'd spend buying 2 sets that didn't work, &/or that the sets that do work from Meritline last just a bit over 1/3 as long as the originals.
Finally, again FWIW, folks that do a LOT of printing AFAIK usually add an ink tank setup, with tubes running from the much larger ink tanks to special cartridges.
