Vertical lines in preview and output results

I notice there are hundreds or thousands of visible vertical lines in the output. While the result looks great from a distance, is this attributed to a setting?

What is the cause of these vertical lines?

Is this slow process the solution? https://www.youtube.com/watch?v=o7a6TIsbn6Q

cheek-with-lines

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.