rgrenaderphoto Loc: Hollywood, CA

Ink cartridges have RFID chips that communicate with the printer electronics and let it know you are not using OEM ink. Ain't witchcraft, it's technology.

drc023 Loc: North Little Rock, Arkansas

That's a definite maybe on the RFID chips. HP was particularly clever about thwarting us evil refillers. I'm not sure how Epson does it, but Canon is somewhat of a big ole pushover. The BCI-6 family of cartridges was the final ones I used that didn't have chips - iP3000 & iP4000 printers. Then chips arrived but didn't do much to stop refilling. From being able to easily disable ink monitoring or using inexpensive chip resetters refilling is a simple and effective way of accomplishing affordable printing. I have three sets of cartridges for my MG6220 and two sets for my Pro-100. All tanks are replaced with a fresh set of refills when any one tank runs low. Both Canon and Epson have now released printers that are designed for inexpensive refilling using their own inks. Canons MegaTank and Epsons EcoTank are realistically priced and while not yet higher end photo quality are more than adequate for most users.

Bunkershot Loc: Central Florida

Are you calibrating your monitor? When you said the problem came on gradually I think that is an indication that your monitor is slowly getting out of calibration. Since my original response to your post I've had numerous discussions with DataColor regarding my Spyder5 calibration software. Even with a new monitor they advise frequent re-calibrations, as often as weekly. I'm loving my Pro 100.