How do you fix a pinhole?
Even in the best of shops, you'll eventually get a pinhole or a fisheye. The best way to fix pinholes is to use screen tape or a blockout pen. If you are using water-based inks, try clear nail polish.
Backlight all newly created screens so you can find any defects with the screen before you go into production. This way, you can easily fill in pinholes to fix issues before they show up on your garments.