Out of stock shows only on main shop page

The “out of stock” image overlay is visible only on my main shop page and does not show on the actual product page. I’m not sure if this is by design, or if it was accomplished by custom coding, or via an admin setting that I cannot find.

How can I make the “out of stock” image overlay appear on product page images?

• This topic was modified 4 years, 10 months ago by motorambler.

The page I need help with: [log in to see the link]