PeterBJ figured it out. I refill by a vacuum method called "Freedom filling". It requires more cleanup than many other methods, and you often get artwork like this as a side effect.
What, is this the first one of the new year? Here's my answer to that disputed Jackson Pollock. They want $100 million for that one, but I'll sell mine for only $50 million.
Disclaimer: my avatar is almost the same picture. But not quite.
I like to do accelerated tests--in direct sunlight or held against a fluorescent tube. With this kind of abuse, all the the third-party black dyes I have tested are among the most unstable inks I have tested. I just use OEM photo black.
On the other hand, all the text pigment inks I have...
After reviewing my tests, I think his result is real, although I am surprised the light was that bright in his kitchen. On printer paper, a few days in the sun will do that to all the third-party dye blacks I have tested. Photo paper is somewhat better, but not immune to fading.
That color in the Pro-100 print is typical of either a sepia-toned print or fading of dye black. Neither would surprise me. Mark McCormick thinks it could be "ink migration". I usually trust his opinion on matters of fading, but in this case I think he made a mistake.
When I first started refilling, I bought and tested different brands of ink and compared them to OEM on five different media (printer paper, 2 OEM photo papers, and two CDs). in three different locations. It took some time, but it didn't cost a lot because I eventually used most of the ink...