Anyone have experience printing on Epson Exhibition Fiber paper with the Epson SC P800? When I use Epson's recommended printing configuration (or several variations), small white spots appear in dense black areas of the print, looking something like fine salt spread on the paper. Admittedly this is apparent only in images with fairly large areas of deep black (which is common for my work, which involves printing deep sky astronomical images, containing dark backgrounds).
This does not occur with the exact same image printed with the same printer on other paper, such as Ultra Premium Luster, and it never happened with the Epson P3800 on Exhibition Fiber paper. I have reproduced the problem with two brand new P800s.
Admittedly I have not pursued this deeply with Epson support but did not get especially helpful answers on initial contacts.