Vertical dots are appearing on my film.
If the dots are a single vertical line it is likely the spiked tracker feed wheels (desktop models) of the printer leaving foot prints on the film as it steps through the wet ink.
Simply clean the printer and print a few pages to PAPER to dry up the wheels.
If the printer has been used “a lot” its internal Waste tank may be full. That is not good as Epson would like you to replace the printer. You may opt to check the internet for ways to OPEN the printer case and find the WASTE tank that is located under and behind the ink cartridges.