With our recent run of 1500 small plates, after it started saying the near new ink cartridge was empty it did something similar.

We had printed out over 1000 with solid very black letters.

I hooked up a different identical printer and the all black text printed about 10 times faster, only a few seconds per page rather than the usual minute or to.

Sounded great at the time and the printed transfer looked black enough.
Actually the finished pressed items didn't look bad, but when placed beside the first ones they did look brownish instead of dark black.

I think the settings got reset to a lower resolution. It was the last of the run and I didn't have time to test it again. In epson it may be listed as something like photo, best photo,draft, text,. If it worked before, sometimes there is a button that says restore defaults.

There is also a dropdown box for choosing the type of paper which will make a difference.

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